bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship of Biological Markers of Body Fat Distribution and Corticosteroidogenic Enzyme Activities in Women with Polycystic Ovary Syndrome
Authors: de Medeiros Sebastião Freitas , de Medeiros Matheus Antonio Souto , Barbosa Bruna Barcelo , Yamamoto Márcia Marly Winck
Published: October 2019

The aim of the study is to determine the impact of different anthropometric measurements of fat distribution on baseline sex-steroid concentrations and corticosteroidogenic enzyme activity in women with polycystic ovary syndrome compared to those with regular menstrual cycles. The current cross-sectional study included 106 normal cycling controls and 268 polycystic ovary syndrome patients. Patients with polycystic ovary syndrome, diagnosed by Rotterdam criteria, were divided in normoandrogenemic (n=91) and hyperandrogenemic (n=177). Anthropometric, biochemical, and hormone parameters were assessed and correlated with corticosteroidogenic enzyme activities in all three groups. Corticosteroidogenic enzyme activities were calculated using product-to-precursor ratios. Regarding sex-steroids individually, anthropometric parameters correlated with the concentrations of several androgens in polycystic ovary syndrome patients, most of them in patients with biochemical hyperandrogenism. The androgen precursors androstenedione, 17-hydroxyprogesterone, and dehydroepiandrosterone were less correlated with anthropometric parameters. The 17,20 lyase activity, in both Δ4 and Δ5 pathways, correlated with several anthropometric measurements in normo- and hyperandrogenemic polycystic ovary syndrome patients. The 17,20 lyase enzyme activity (Δ4 pathway) also correlated with conicity index, visceral adiposity index, and lipid accumulation product in the control group. 17-Hydroxylase activity positively correlated with waist-height ratio in both polycystic ovary syndrome groups. In contrast, 17-hydroxilase negatively correlated with the conicity index. Anthropometric markers of adiposity are associated with androgen levels and their precursors in blood. Body fat distribution correlates with the activities of some steroidogenic enzyme in both normo-and hyperandrogenemic polycystic ovary syndrome phenotypes. The molecular mechanisms involved in these associations are largely unclear and more investigations are required.
Top-Ten Pitfalls in Rotator Cuff Ultrasound
Authors: Griffith James F.
Published: October 2019

Shoulder ultrasound is a commonly performed imaging study that can accurately determine the presence of rotator cuff tendinosis and tears, as well as subacromial-subdeltoid bursal and long head of biceps tendon pathology. High accuracy depends on an awareness of imaging pitfalls that can be encountered and lead to over- or underdiagnosis of rotator cuff pathology. Ten common pitfalls of rotator cuff ultrasound scanning are presented along with ways to avoid these pitfalls.
Top-Ten Pitfalls When Imaging Osteoporosis
Authors: Cheng Xiaoguang , Griffith James F. , Chan Wing P.
Published: October 2019

Osteoporosis will become even more prevalent as the world population ages. Radiologists are well placed to recognize this disease that often first manifests on routine imaging studies. Most radiologists encounter patients with osteoporosis during their normal daily reporting. Osteoporosis is prone to potential pitfalls on imaging, and the more common of these are outlined in this review.
Musculoskeletal Tuberculosis: A Multifaceted Foe
Authors: Kumar Uma , Dasgupta Sauvik
Published: October 2019

Tuberculosis (TB) still remains a global epidemic, and India accounts for one-fourth of the world's TB burden. The incidence of extrapulmonary TB has relatively remained constant, but with the introduction of antitumor necrosis factor, there has been a surge in pulmonary and extrapulmonary TB cases presenting to rheumatologists. Musculoskeletal TB accounts for 10 to 30% of all cases of extrapulmonary TB, with spondylitis (Pott's spine) being the most common manifestation. Manifestations mimicking autoimmune spondylitis are seen in 10% of cases. Tubercular arthritis most commonly presents with large joint monoarthritis, but oligo- or polyarticular involvement is also seen. Poncet's disease is a form of reactive arthritis occurring in patients with pulmonary or extrapulmonary TB, which is rarely seen with good response to antitubercular treatment. Quite often, there is delay in the diagnosis of musculoskeletal TB due to absence of constitutional symptoms. Treatment of musculoskeletal TB involves prolonged course of antitubercular treatment, and surgical interventions are limited to special cases.
Smoking and Tobacco Use: Ill Effects on Reproductive, Maternal, Newborn, Child Health, and Adolescent (RMNCHA) Program—A Review
Authors: Mittal Suneeta
Published: October 2019

Most people are aware that tobacco causes cancer, heart disease, chronic obstructive pulmonary disease, and major health problems, leading to high morbidity and mortality; however, many are not aware of its ill effects on the reproductive health of men and women as well as their children. This article has summarized the current research evidence from literature search to date, including prevalence of tobacco use, types of tobacco use, its effects on male and female fertility, pregnancy and their progeny in utero, neonatal period, childhood, adolescence, and subsequent well-being, with both active and passive smoking and smokeless tobacco use. Although antitobacco campaigns show horrifying visuals linked to tobacco use, not much progress has been made in controlling its use. Publicizing these harmful effects on pregnancy and progeny, making public aware, screening women coming for infertility or antenatal care on any form of tobacco use, and helping them to quit tobacco use may help the National Tobacco Control program, as parents are more concerned if they learn that there is harm to their fertility and progeny. Indirectly, it will help to improve reproductive, maternal, neonatal, child, and adolescent health.
Efficacy of Phenylephrine in Preventing Hemodynamic Responses of Oxytocin during Elective Cesarean Section: A Randomized, Double-Blind, Controlled Trial
Authors: Mohta Medha , Kumar Vijay , Agarwal Rachna , Chilkoti Geetanjali T. , Duggal Sakshi
Published: October 2019

This study compared hemodynamic changes and occurrence of complications following oxytocin administration with a prior injection of phenylephrine 100 μg or normal saline during elective cesarean section. Sixty-six healthy term parturients with uncomplicated, singleton pregnancy undergoing elective cesarean section under spinal anesthesia were studied. They received either intravenous phenylephrine 100 μg or normal saline before oxytocin 3 IU was administered over 30 seconds. Oxytocin dose was repeated depending on the adequacy of uterine tone. There was no significant change in systolic, diastolic, and mean arterial pressures during the initial 3 minutes following oxytocin administration in the phenylephrine group but a significant fall in mean and diastolic pressures in the saline group. Heart rate did not change significantly, and no significant complications occurred in either of the groups. To conclude, phenylephrine 100 μg administered before oxytocin injection maintained hemodynamic parameters better than normal saline injection during elective cesarean section.
Aggressive, Multidisciplinary Staged Microsurgical Resection of a Giant Cervicomedullary Junction Chordoma
Authors: Sayyahmelli Sima , Dogan Ihsan , Wieland Aaron M. , Pyle Mark , Başkaya Mustafa K.
Published: October 2019

Chordomas of the cranial base are locally destructive tumors since they are surrounded by significant complex neurovascular structures. Thus, their surgical removal is challenging, recurrence rates are high, and their therapeutic strategies remain controversial.

In this video, we present a 47-year-old man with a recent onset of swallowing difficulties, hoarseness, and weight loss for several weeks. In the neurological examination, he had complete paralysis of the 9th, 10th, 11th, and 12th cranial nerves. Magnetic resonance imaging (MRI) showed a heterogeneously enhancing expansile invasive mass lesion centered within the clivus and involving the C1, the occipitocervical junction, the retropharynx, and the hypoglossal canal. The decision was made to proceed with multiple staged surgeries. In the first surgical stage, we performed a mastoidectomy with the infralabyrinthine approach to perform a test clip ligation of the sigmoid sinus and to resect the tumor component that extended into the infralabyrinthine space. In the second stage, we performed a far-lateral transcondylar approach for tumor resection and occipitocervical fusion. In the third stage, we used a transoral approach with endoscopic assistance to complete the excision of the remaining tumor in the retropharyngeal space and anterior aspect of C1 and C2 bodies that were not accessible in the first two stages.

The surgeries and postoperative course were uneventful. Postoperative MRI showed a gross total resection of the tumor. Histopathology indicated a chordoma. The patient subsequently received proton radiotherapy and has continued to do well without recurrence at 14 months' follow-up.

The link to the video can be found at: https://youtu.be/uP9OSlKg_rE.
Bacterial Pneumonias in Immunocompromised Patients
Authors: Van de Louw Andry , Mirouse Adrien , Peyrony Olivier , Lemiale Virginie , Azoulay Elie
Published: October 2019

With the overall improvement in survival of cancer patients and the widespread use of novel immunotherapy drugs for malignant as well as nonmalignant diseases, the prevalence of immunosuppression is rising in the population. Immunocompromised patients are particularly exposed to pulmonary infections which remain a leading cause for acute hypoxic respiratory failure and intensive care unit admission. Although fungal or opportunistic infections are always a concern, bacterial pneumonia remains the most common cause of pulmonary infection, is associated with a significant mortality, and has some specificity in this population. Adequate and timely prevention, diagnosis, and management of bacterial pneumonias require knowledge about the complex interplay between host factors (type and severity of immunosuppression) and bacterial pathogenesis, to improve the outcome. We provide an overview of bacterial pneumonias in immunocompromised patients including their epidemiology, risk factors with respect to the pattern of immunosuppression, microbiological characteristics, diagnostic approach, management, and prevention.
Small Dense Low-Density Lipoprotein: Biomarker or Potential Drug Target?
Authors: Samanta Basabdatta
Published: October 2019

Ischemic heart disease is currently an epidemic affecting individuals worldwide. Increased incidence along with earlier onset of disease has led to the constant search for biomarkers that will help in earlier identification and treatment of at risk individuals. Small dense low-density lipoprotein (sdLDL) is the atherogenic subtype of low-density lipoprotein (LDL). It is smaller in size and higher in density in comparison to other LDL subtypes. Higher levels of sdLDL have beenfound to be associated with increased incidence of ischemic heart disease and adverse outcomes. Properties including decreased resistance to oxidative stress and prolonged residence time in the circulation account for its increased atherogenic potential. Hence intervention approaches targeting sdLDL directly in at risk individuals may be beneficial.

Genetic, lifestyle, and environmental factors affect sdLDL levels.But the main determining factor is the level of triglycerides (TGs). Higher TG levels are associated with higher levels of very low density lipoprotein (VLDL) 1 and sdLDL. Various drugs have been used for targeting sdLDL with varying outcomes; drugs tried out include statins, fibrates, niacin, cholesterol ester transfer protein inhibitors and sodium-glucose co-transporter-2 inhibitors. Future prospects include modification of enzymes involved in fatty acid and TG synthesis, for example, lipoprotein lipase and acyl CoA carboxylase. However, further research is still necessary to draw clear guidelines for sdLDL reduction therapy in coronary artery disease treatment and prevention.
Visual Evidence: Increasing Usability of Systematic Reviews in Health Systems Guidelines Development
Authors: Smith Connor J. , Jungbauer Rebecca M. , Totten Annette M.
Published: October 2019

Background Integration of evidence from systematic reviews is an essential step in the development of clinical guidelines. The current practice for reporting uses a static structure that does not allow for dynamic investigation. A need exists for an alternate reporting modality to facilitate dynamic visualization of results to match different end-users' queries.

Objectives We developed a dynamic visualization of data from a systematic review using the commercial product Tableau and assessed its potential to permit customized inquiries.

Methods Data were selected and extracted from a previously completed systematic review. The resulting dataset was then used to develop an interactive, web-based report designed for use by a guidelines development committee.

Results A novel example of combining existing reporting standards for systematic review data and modern reporting tools was developed to investigate potential benefits of a dynamic report. Demonstrations of the report to clinicians sitting on previous and future guideline committees received positive feedback for its potential benefit in guidelines development. The report received a runner-up award during the design challenge at the 2018 Workshop on Visual Analytics in Health Care.

Conclusion The use of interactive, accessible data may increase the use of systematic reviews and aid decision makers in developing evidence-based practice changes.
Viral Encephalitis: A Hard Nut to Crack
Authors: Shukla Alka , Gangwar Mayank , Rastogi Sonam , Nath Gopal
Published: October 2019

Viral encephalitis is inflammation of brain that manifests as neurological complication of viral infections. There are quite a good number of viruses, for example, human herpes virus, Japanese encephalitis, and enteroviruses that can result in such a dreadful condition. Geographical location, age, gender, immune status, and climatic conditions also contribute to the establishment of this disease in an individual. Clinical signs and symptoms include fever, headache, altered level of consciousness, changed mental status, body ache, seizures, nausea, and vomiting. Effective management of this disease relies on timely diagnosis that in turn depends on apt and suitable investigation techniques. Traditional investigations have thinned out these days owing to the fact that advanced molecular technologies have been introduced to the diagnostic field. Treatment of viral encephalitis mainly involves symptomatic relieve from fever, malaise, myalgia along with measures to reduce viral load in the patient. This review mentions about all the possible aspects of viral encephalitis starting from etiology to the management and preventive measures that include immunization and vector control.
Survey of attitudes, materials and methods preferred in root canal therapy by general dental practice in Turkey: Part 1
Authors: Unal Gul Celik , Kaya Bulem Ureyen , Tac Ali Gurhan , Kececi Ayse Diljin
Published: October 2019

Objective: To gather information on the materials and methods employed in root canal treatment by dentists in Turkey

Methods: A questionnaire was distributed to 1,527 dentists who attended the Turkish Dental Association Congress. Respondents were asked to choose one or more suitable answers for the questions. Data was gathered for demographic and professional information regarding stages, materials, and methods commonly used in endodontic therapy. The collected data was analyzed using the statistical package SPSS. Descriptive statistics were given as frequencies (n) and percent (%). Chi-square (χ2) test was used to investigate the influence of gender and the years of professional activity for the materials and techniques employed.

Results: The response rate was 49%. A total of 97% of respondents were working in a general dental practice. Of respondents, 44% were using an agent containing arsenic or aldehyde. Only 5.1% of the respondents preferred the rubber dam isolation method. Sodium hypochlorite was the most popular choice (73%) as a root canal irrigation solution. Calcium hydroxide was the most commonly used medicament (53%). Most of the practitioners (77%) preferred radiographs for working-length determination. Root canal preparation done solely with K-Files or in combination with other instruments was preferred by 73.1% of the respondents. Ni-Ti hand or rotary files were used by 79.7% of the practitioners. Polymer based root canal sealers were the sealers most frequently chosen (48.4%). The majority of the respondents (66.2%) preferred cold lateral condensation as an obturation technique. Gender affected the preference of intracanal medicament, periapical radiographs for working-length determination, root canal instrument, root canal sealers, and root canal obturation technique (P<.05). Years of professional experience affected the preference of devitalizing agents, irrigation solutions, intracanal medicament, root canal instrument, root canal sealer, and root canal obturation technique (P<.05).

Conclusions: It is clear that a number of dentists, irrespective of the time elapsed since their graduation, relied on techniques, and used products and materials that are currently favoured by expert opinion. Unfortunately, it was noted that some practitioners are still using arsenic- and aldehyde- containing devitalizing agents, and most did not use rubber dam as an isolation method. (Eur J Dent 2012;6:376-384)
Symmetries of the space of solutions to special double confluent Heun equations of integer order
Authors: Tertychniy Sergey I.
Published: October 2019

This paper investigates the triplet of linear operators that determines automorphisms of the set of solutions to special double confluent Heun equations of integer order. Their pairwise composition rules are computed in explicit form. It is shown that, under the conditions motivated by physical applications, these operators generate the group of symmetries of the linear space of solutions that is isomorphic to the dihedral group, provided the monodromy equivalence relation is applied. On the corresponding projective space, the symmetry group reduces to the Klein group. The results presented in this paper have implications for the modeling of Josephson junctions.
A custom built lathe designed for in operando high-energy x-ray studies at industrially relevant cutting parameters
Authors: Rogström L. , Chen Y. H. , Johansson Jõesaar M. P. , Eriksson J. , Fallqvist M. , Andersson J. M. , Schell N. , Odén M. , Birch J.
Published: October 2019

We present a custom built lathe designed for in operando high-energy x-ray scattering studies of the tool-chip and tool-workpiece contact zones during operation. The lathe operates at industrially relevant cutting parameters, i.e., at cutting speeds ≤400 m/min and feeds ≤0.3 mm/rev. By turning tests in carbon steel, performed at the high-energy material science beamline P07 at Petra III, DESY, Hamburg, we observe compressive strains in TiNbAlN and Al2O3/Ti(C, N) coatings on the tool flank face during machining. It is demonstrated that by the right choice of substrate and coating materials, diffraction patterns can be recorded and evaluated in operando, both from the tool-workpiece and tool-chip contacts, i.e., from the contact zones between the tool and the workpiece material on the tool flank and rake faces, respectively. We also observe that a worn tool results in higher temperature in the tool-chip contact zone compared to a new tool.
Design and fabrication of a resonant-cavity electrode microwave discharge device and its performance in argon and xenon plasma
Authors: Zhang Zhongkai , Liu Yu , Cao Jinxiang , Yu Pengcheng , Zhang Xiao , Wang Jian
Published: October 2019

A new configuration of a resonant-cavity electrode microwave discharge device is developed in this work. In the device, a hollow electrode antenna is used for microwave transporting, and a well-designed resonant-cavity could enhance the absorption of the microwave power. A quartz cover is adopted to seal the vacuum and insulate the antenna from plasma, which greatly reduces the heat accumulation on the antenna. A magnetic field coil made by multiple-turn enameled wires is designed which could generate a strong magnetic field based upon a low-current power supply. In the plasma chamber, a distinctive L-shape probe is designed to measure the parameter distribution, and the two-dimensional parameters can be measured with the simple structure. In addition, the characteristic parameters such as electron density and temperature are measured in the chamber with a single probe, and the electron density distribution and spectrum are compared in argon and xenon plasma, which suggests that the microwave plasma device has good adaptability and functionality.
Development of small hydropower in China 1990–2015: Province-domain patterns of temporal-spatial evolution
Authors: Qiao Haijuan , Huang Zhou , Chen Weiyi , Zhang Conglin , Ou Chuanqi , Zhang Shuang
Published: October 2019

At present, no quantitative method has been developed to analyze province-level data of small hydropower development in China. Knowledge of its temporal-spatial patterns can be conducive to predicting and planning for its future. For this reason, the study sets out to approach it as two problems: Development level evaluation and spatial distribution. Specifically, panel data of provinces or equivalent administrative units were used to establish an evaluation system covering the fields of economy, society, eco-environment, and resources; an evaluation model was formulated using the entropy weight technique for order preference by similarity to ideal solution method and theory of coupling coordination; its trends were discovered by regression analysis; the spatial distribution model was built by clustering analysis and center of gravity analysis. Results indicate that, during the 1990–2015 period, while small hydropower developed to their respective steady-state levels, some gaps still exist in the general trend of small hydropower among provinces. The center of gravity of small hydropower development displayed a movement toward the Northwest. Based on clustering of scores in the four dimensions and coupled coordination, its spatial distributions can be divided into three zones: Highly coordinated, relatively coordinated, and uncoordinated, and its temporal patterns can be described as three stages: Rise with fluctuations, unbalanced and uncoordinated development, and steady rise. Policy suggestions are provided on this basis.
Characterization of a 100 micrometer-scale cryogenically cooled gas jet for near-critical density laser-plasma experiments
Authors: Salehi F. , Goers A. J. , Feder L. , Miao B. , Woodbury D. , Milchberg H. M.
Published: October 2019

We present the design and characterization of a thin, high density pulsed gas jet for use in the study of near critical laser plasma interactions with ultrashort Ti:sapphire laser pulses. The gas jet uses a range of capillary nozzles with inner diameters between 50 and 150 μm and is operated in the sonic regime. Cryogenic cooling of the gas valve body to −160 °C provides the necessary density enhancement for reaching overcritical plasma densities at λ = 800 nm (Ncr ≈ 1.7 × 1021 cm−3) using hydrogen gas at jet backing pressures below 1000 psi. Under certain conditions, fast expansion of the gas from a nozzle can lead to formation of clusters; here, we use our previously demonstrated all-optical method to estimate the cluster mean size and density. For the jets studied here, we find that cluster formation only begins at distances from the nozzle exit greater than a few times the nozzle orifice diameter.
Weakly coupled triplet pair states probed by quantum beating in delayed fluorescence in tetracene crystals
Authors: Wang Zhiwei , Zhang Chunfeng , Wang Rui , Wang Guodong , Wang Xiaoyong , Xiao Min
Published: October 2019

The intermediate state of a correlated triplet pair [1(TT)] is pivotal for understanding the mechanism of the singlet fission process in molecule systems. Recently, a spatially separated state of a triplet pair [1(T⋯T)] has been proposed to drive the dissociation of exchange-coupled 1(TT) into free triplets. Here, we study the correlated triplet pairs by monitoring quantum beats in delayed fluorescence from tetracene crystals upon applying magnetic fields of different amplitudes and alignments. We argue that the triplet pairs probed by the quantum beat spectrum are weakly coupled, i.e., the spatially separated 1(T⋯T) state. The experimental data suggest the existence of a direct channel of S1 → 1(T⋯T) in addition to the widely accepted channel of S1 → 1(TT) → 1(T⋯T) for singlet fission. Our work suggests that the quantum beat spectrum is a useful tool to directly probe the 1(T⋯T) state which is valuable for elucidating the intrinsic mechanism of singlet fission.
Highly stretchable and conductive composite films with a multistoried film and pillar structure of gold on elastic substrates
Authors: Zhao Yang , Li Chenguang , Yu Mei , Yu Zhe
Published: October 2019

A novel structure is designed for developing highly stretchable electrodes with a multistoried film and pillar (mFNP) structure of gold on an elastic substrate. The mFNP structure inspired by the percolation theory increases the conductive pathways in the stretchable electrodes considerably by connecting the gold layers with gold nanopillars and thus enhances the stretchability. The mFNP structure can be achieved by two methods. For the mFNP structure fabricated by the polycarbonate membrane mask method, the stretchability of the stretchable electrodes increases from 90% to 130% for single and double-storied structures, while for the porous layer method, the stretchability increases from 80% to 120% and 140% for single, double, and five-storied structures, respectively. The long term stability of the mFNP structure is tested by stretching cycles of 1000 times. In addition, stretchable microelectrode arrays based on this mFNP structure are developed to monitor the electrocorticogram (ECoG) signal of a rat with epilepsy successfully, as an effective and friendly bioelectronic interface. The novel structure improves the stretchability and also reduces the electrode size. This idea can be applied to other types of stretchable electronic design, enabling the stretchable electronics to wider applications.
An optimized 3D displacement probe using sensitivity-compliance joint model
Authors: Zheng Weikang , Liu Zhigang , Li Xinbo , Guo Junkang
Published: October 2019

The existing analytical methods for 3D probes with the monolithic elastic mechanism are usually one-dimensional or two-dimensional, while the contact force acting on the stylus ball is three-dimensional. The mismatch between the methods and the actual force suppresses the performance optimization of the elastic mechanism. This paper proposes a 3D multivariate-decoupling sensitivity-compliance joint model of a 3D probe with the Hexflex mechanism. The decoupling relationships of the system input, structural parameters, and system output are thus revealed. The key parameters affecting probe performance, namely, output compliance, input compliance, and sensitivity, are obtained through the joint model, which contributes to an optimized mechanism with the same topological configuration with the Hexflex mechanism. Finite element analysis (FEA) shows that the output compliance, input compliance, and sensitivity of the optimized probe are increased by 157.7%, 48.4%, and 78.6%, respectively. The resolution and contact force of the probe are greatly improved. The calibration experiment of the prototype validates the theoretical analysis and FEA, showing significant consistency. Furthermore, this paper analyzes the linearity, repeatability, and measurement deviations of the optimized probe. Compared with the Renishaw probe TP200 and other smaller probes, the probe has better performance in compliance and sensitivity.
Formation free energies of clusters at high supersaturations
Authors: Nie Chu , Geng Jun , Marlow William H.
Published: October 2019

The Helmholtz free energy of a constrained supersaturated vapor with a cluster size distribution consisting of clusters of various sizes is modeled as a mixture of hard spheres of various sizes attracting each other. This model naturally takes into account monomer-monomer and monomer-cluster interactions, so it implicitly pertains to nonideal gases, unlike prior work. Based on this model, the expressions for the equilibrium concentration and the formation free energies of clusters in a metastable supersaturated vapor have been derived. These results indicate that the widely used formula, ni = n1exp(−βΔGi), that computes the formation free energy of a cluster does not work at high supersaturations. As an example, the formation free energies of clusters with Stillinger’s physical cluster definition in metastable, highly supersaturated vapors interacting via Lennard-Jones potential are studied using these expressions. Noticeable differences have been found for both the formation free energies of clusters and sizes of the critical clusters computed from our proposed expressions vs those from the formula ni = n1exp(−βΔGi).
Design of dynamic screw pinch experiments for magnetized liner inertial fusion
Authors: Shipley G. A. , Jennings C. A. , Schmit P. F.
Published: October 2019

Magnetic implosion of cylindrical metallic shells (liners) is an effective method for compressing preheated, premagnetized fusion fuel to thermonuclear conditions [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)] but suffers from magneto-Rayleigh–Taylor instabilities (MRTI) that limit the attainable fuel pressure, density, and temperature. A novel method proposed by Schmit et al. [Phys. Rev. Lett. 117, 205001 (2016)] uses a helical magnetic drive field with a dynamic polarization at the outer surface of the liner during implosion, reducing (linear) MRTI growth by one to two orders of magnitude via a solid liner dynamic screw pinch (SLDSP) effect. Our work explores the design features necessary for successful experimental implementation of this concept. Whereas typical experiments employ purely azimuthal drive fields to implode initially solid liners, SLDSP experiments establish a helical drive field at the liner outer surface, resulting in enhanced average magnetic pressure per unit drive current, mild spatial nonuniformities in the magnetic drive pressure, and augmented static initial inductance in the pulsed-power drive circuit. Each of these topics has been addressed using transient magnetic and magnetohydrodynamic simulations; the results have led to a credible design space for SLDSP experiments on the Z Facility. We qualitatively assess the stabilizing effects of the SLDSP mechanism by comparing MRTI growth in a liner implosion simulation driven by an azimuthal magnetic field vs one driven with a helical magnetic field; the results indicate an apparent reduction in MRTI growth when a helical drive field is employed.
Revisiting the clap-and-fling mechanism in small wasp Encarsia formosa using quantitative measurements of the wing motion
Authors: Cheng Xin , Sun Mao
Published: October 2019

The ideal clap-and-fling mechanism is described as: clap, the leading edges of the wings touch and then the wings rotate around the leading edge, closing the gap between the wings and producing a vertical force; fling, the wings rotate around the trailing edge or “fling open,” generating a vertical force (the drag required to clap or fling the wings can be 6–10 times larger than the vertical force). Here, we revisit the mechanism from the perspective of wing motion and force production, based on our measured quantitative data and flow computations, and suggest certain modifications to its description: In the clap, the wings rotate to a large angle of attack before they are close to each other and they move close to each other with the wing surface almost vertical, and then they move vertically upwards; i.e., the ideal clap motion is far from the real one. The fling is like the ideal one, except that there is a separation (approximately 0.2 chord length) between the wings. During the clap, there is no large vertical force like that in the ideal clap; however, the clapped wings can reduce the downward frictional drag in their upward motion. During the fling, a large vertical force is produced, like that in the ideal fling, but the drag required to fling the wings is no longer 6–10 times larger than the vertical force and it is even a little smaller than the vertical force.
Seed priming in field crops: potential benefits, adoption and challenges
Authors: Farooq Muhammad , Usman Muhammad , Nadeem Faisal , Rehman Hafeez ur , Wahid Abdul , Basra Shahzad M. A. , Siddique Kadambot H. M.
Published: October 2019

Seed priming is a presowing technique in which seeds are moderately hydrated to the point where pregermination metabolic processes begin without actual germination. Seeds are then redried to near their actual weight for normal handling. Seeds can be soaked in tap water (hydropriming), aerated low-water potential solutions of polyethylene glycol or salt solutions (KNO3, KH2PO4, KCl, NaCl, CaCl2 or MgSO4; osmopriming), plant growth regulators, polyamines (hormonal priming), plant growth-promoting bacteria (biopriming), macro or micronutrients (nutripriming) or some plant-based natural extracts. Here, we review: (1) seed priming as a simple and effective approach for improving stand establishment, economic yields and tolerance to biotic and abiotic stresses in various crops by inducing a series of biochemical, physiological, molecular and subcellular changes in plants; (2) the tendency for seed priming to reduce the longevity of high-vigour seeds and improve the longevity of low-vigour seeds; (3) the advantages of physical methods of seed priming to enhance plant production over conventional methods based on the application of different chemical substances; (4) the various physical methods (e.g. magneto-priming and ionising radiation, including gamma rays, ultraviolet (UV) rays (UVA, UVC) and X-rays) available that are the most promising presowing seed treatments to improve crop productivity under stressful conditions; and (5) effective seed priming techniques for micronutrient delivery at planting in field crops. Seed priming as a cost-effective approach is being used for different crops and in different countries to improve yield, as a complementary strategy to grain biofortification and in genetically improved crop varieties to enhance their performance under stress conditions, including submergence and low phosphorus. Some of the challenges to the broad commercial adaption of seed priming include longevity of seeds after conventional types of priming under ambient storage conditions and a lack of studies on hermetic packaging materials for extended storage.
Genome-wide identification of the glutathione transferase superfamily in the model organism Brachypodium distachyon
Authors: Gallé Ágnes , Benyó Dániel , Csiszár Jolán , Györgyey János
Published: October 2019

The detoxification of harmful metabolites can determine the effectiveness of plant stress responses. Scavenging some of these toxic stress by-products through the reduced form of glutathione is catalysed by members of the glutathione transferase (GST) enzyme superfamily. The involvement of these enzymes was studied in the model organism Brachypodium distachyon (L.)P.Beauv. Bd21 and in its derivative Bd21-3, a more drought tolerant line. Osmotic stress treatment resulted in a decrease in the water potential of both Brachypodium genotypes, the difference between the control and treated plant’s ψw decreased by the last sampling day in Bd21-3, suggesting some degree of adaptation to the applied osmotic stress. Increased GST activity revealed a severe defence reaction against the harmful imbalance of the redox environment. Screening for the gene sequences led to the identification of 91 full-length or partial GST sequences. Although purple false brome has a relatively small genome, the number of identified GST genes was almost as high as the number predicted in wheat. The estimation of GST expression showed stress-induced differences: higher expression levels or the fast induction of BdGSTF8, BdGSTU35 and BdGSTU42 gene products presumably indicate a strong detoxification under osmotic stress.
Soft metrology based on machine learning: a review
Authors: Vallejo Marcela , de la Espriella Carolina , Gómez-Santamaría Juliana , Ramírez-Barrera Andrés Felipe , Delgado-Trejos Edilson
Published: October 2019

Soft metrology has been defined as a set of measurement techniques and models that allow the objective quantification of properties usually determined by human perception such as smell, sound or taste. The development of a soft metrology system requires the measurement of physical parameters and the construction of a model to correlate them with the variables that need to be quantified. This paper presents a review of indirect measurement with the aim of understanding the state of development in this area, as well as the current challenges and opportunities; and proposes to gather all the different designations under the term soft metrology, broadening its definition. For this purpose, the literature on indirect measurement techniques and systems has been reviewed, encompassing recent as well as a few older key documents to present a time line of development and map out application contexts and designations. As machine learning techniques have been extensively used in indirect measurement strategies, this review highlights them, and also makes an effort to describe the state of the art regarding the determination of uncertainty. This study does not delve into developments and applications for human and social sciences, although the proposed definition considers the use that this term has had in these areas.
Empirically based spatial projections of US population age structure consistent with the shared socioeconomic pathways
Authors: Striessnig Erich , Gao Jing , O’Neill Brian C , Jiang Leiwen
Published: October 2019

Spatially-explicit population projections by age are increasingly needed for understanding bilateral human–environment interactions. Conventional demographic methods for projecting age structure experience substantial challenges at small spatial scales. In search of a potentially better-performing alternative, we develop an empirically based spatial model of population age structure and test its application in projecting US population age structure over the 21st century under various socioeconomic scenarios (SSPs). The model draws on 40 years of historical data explaining changes in spatial age distribution at the county level. It demonstrates that a very good model fit is achievable even with parsimonious data input, and distinguishes itself from existing methods as a promising approach to spatial age structure modeling at the global level where data availability is often limited. Results suggest that wide variations in the spatial pattern of county-level age structure are plausible, with the possibility of substantial aging clustered in particular parts of the country. Aging is experienced most prominently in thinly populated counties in the Midwest and the Rocky Mountains, while cities and surrounding counties, particularly in California, as well as the southern parts of New England and the Mid-Atlantic region, maintain a younger population age structure with a lower proportion in the most vulnerable 70+ age group. The urban concentration of younger people, as well as the absolute number of vulnerable elderly people can vary strongly by SSP.
Exploring trends in wet-season precipitation and drought indices in wet, humid and dry regions
Authors: Funk Chris , Harrison Laura , Alexander Lisa , Peterson Pete , Behrangi Ali , Husak Greg
Published: October 2019

This study examines wet season droughts using eight products from the Frequent Rainfall Observations on GridS database. The study begins by evaluating wet season precipitation totals and wet day counts at seasonal and decadal time scales. While we find a high level of agreement among the products at a seasonal time scale, evaluations of 10 year variability indicate substantial non-stationary inter-product differences that make the assessment of low-frequency changes difficult, especially in data-sparse regions. Some products, however, appear more reliable than others on decadal time scales. Global time series of dry, middle, and wet region standardized precipitation index time series indicate little coherent change. There is substantial coherence in year-to-year variations in these time series for the better-performing products, likely indicative of skill for monitoring variations at large spatial scales. During the wet season, the data do not appear to indicate widespread global changes in precipitation, reference evapotranspiration (RefET) or Standardized Precipitation Evapotranspiration Index (SPEI) values. These data also do not indicate a global shift towards increasing aridity. Focusing on SPEI values for dry regions during droughts, however, we find modest increases in RefET and decreases in SPEI when wet season precipitation is below normal. Dry region SPEI values during droughts have decreased by −0.2 since the 1990s. The cause of these RefET increases is unclear, and more detailed analysis will be needed to confirm these results. For wet regions, however, the majority of products appear to indicate increases in wet season precipitation, although many products perform poorly in these regions due to limited observation networks, and estimated increases vary substantially. Synopsis: Our analysis indicates a lack of increasing aridity at global scales, issues associated with non-stationary systematic errors, and concerns associated with increases in reference evapotranspiration in global dry regions during droughts.
A short review on recent trends and applications of thermoelectric generators
Authors: Suraparaju Subbarama Kousik , Kartheek Gudapati , Sunil Reddy Gummalla Venkata , Natarajan Sendhil Kumar
Published: October 2019

The basic needs of the society were food, water and energy. The nexus between food, water and energy is unavoidable. Energy is the key element for the survival of all the living beings on the Earth. Energy crisis and environment deterioration are the two most faced glitches of the current scenario. Thermo electricity is one of the promising solutions for energy crisis that is experiencing in this 21st century. This particular article gives the brief description about the principle of thermoelectric devices and their necessity, classification and the applications of thermoelectric generators (TEG’s). Also, this paper gives a short description on materials, design and optimization of TEG’s. It concludes with the future research direction in the realm of thermo electricity generation.
Energy and Life Cycle Assessment of Solar Assisted Microwave Pyrolysis of Waste Biomass
Authors: Santhoshkumar A. , Ramanathan Anand
Published: October 2019

In this proposed work focused on energy efficient solar assisted pyrolysis for biofuel synthesis from different biomass. In recent days solar-powered microwave assisted pyrolysis in increasing the research attention towards higher energy recovery from the waste biomass. Microwave-assisted pyrolysis has promoted by different researchers due to lower energy consumption, faster heating rate and uniform volumetric heating of feed. Compare to electrical and thermal pyrolysis; microwave assisted pyrolysis in increasing the process efficiency due to higher energy recovery and higher hydrogen production. Thus, Microwave-assisted pyrolysis combined with solar energy increase the economic feasibility of the pyrolysis process. To recover more energy from the waste, one must reduce the input power supply and has to improve the process efficiency. So, this proposed project concentrates on solar-powered microwave pyrolysis which will eliminate the need for input power supply. Concentrator Photo-Voltaic (CPV) systems are most likely to produce a massive amount of energy per rated power and module active area. CPV system produces around 2.5 times higher energy per module active area and around 1.3 times higher energy per rated power. Char and ash obtained from the pyrolysis process will be converted into activated carbon and further sintering at a higher temperature for converting into brick form. This reusable solid activated carbon may decrease the processing time by 50%, and raise the temperature around double the time faster compared to the conventional pyrolysis. Compared to the conventional pyrolysis, it is expected that the liquid fuel may increase by 30% due to the fast heating rate. Pyrolysis oil comprises of different chemical functional groups such as sulphur, carbonyls. The phenolic carboxyls compounds provide potentials simultaneously challenging for commercial usage. The hydrocracking and catalytic cracking are the recent technologies used in current research. The usage of hydrogen and catalyst degradation are the major challenges in current technology. To solve this problem, oxidation with ozone would be used as an efficient way for upgradation of biofuel. The life cycle assessment for the entire process is necessary to determine the carbon feet print to the environment.
Production of Bio-Oil from Soapnut seed by Microwave Pyrolysis
Authors: Mathiarasu A. , Pugazhvadivu M.
Published: October 2019

Biomass is one of the potential source of renewable energy to meet the need of alternative fuels. Biomass can be converted into useful energy by thermochemical conversion processes such as gasification, combustion and pyrolysis. Microwave pyrolysis a non-conventional method of heating for the production of pyrolytic bio-oil, char and gas. In this work, soapnut seed is used for the bio-oil production by microwave pyrolysis. The experimental setup used in this work consists of a microwave oven of 2.45 GHz frequency with maximum input power of 800W. In this work, temperature distribution and pyrolytic products yield from the pyrolysis of soapnut with respect to microwave power input are studied. The microwave pyrolysis experiments are conducted at power densities of 8 W/gm, 7 W/gm & 6 W/gm for 20 minutes. The experimental shows that the bio-oil yield (50 wt %) is the highest at 7 W/gm. The flash point, viscosity and calorific value of the pyrolytic bio-oil are measured and presented. The results indicated that the bio-oil produced by the microwave pyrolysis can be upgraded and used as a potential fuel for IC engines.