bluuebunny/crossref_metadata_2025 huggingface dataset:
Trump's Abortion‐Promoting Aid Policy
Authors: Latham Stephen R.
Published: July 2017

On the fourth day of his presidency, Donald Trump reinstated and greatly expanded the “Mexico City policy,” which imposes antiabortion restrictions on U.S. foreign health aid. In general, the policy has prohibited U.S. funding of any family‐planning groups that use even non‐U.S. funds to perform abortions; prohibited aid recipients from lobbying (again, even with non‐U.S. money) for liberalization of abortion laws; prohibited nongovernment organizations from creating educational materials on abortion as a family‐planning method; and prohibited health workers from referring patients for legal abortions in any cases other than rape, incest, or to save the life of the mother. The policy's prohibition on giving aid to any organization that performs abortions is aimed at limiting alleged indirect funding of abortions. The argument is that if U.S. money is used to fund nonabortion programs of an abortion‐providing NGO, then the NGO can simply shift the money thus saved into its abortion budget. Outside the context of abortion, we do not reason this way. And the policy's remaining three prohibitions are deeply troubling.
“Please amputate my child's arms”
Authors: Devereaux Mary , Kuo Dennis John
Published: July 2017

Jeremy sustained bilateral complete brachial plexus injuries in an auto collision on an icy road a month before his third birthday. The accident rendered both upper extremities completely flail and insensate: he has no motor or sensory function of his shoulders, elbows, wrists, or digits. Jeremy does, however, have normal function of the lower extremities. Physical therapists have worked with the child for over a year with no noted improvement in arm function. Jeremy falls frequently, causing injury to his face and head, and occasionally, his arms get twisted or caught in his crib and his fingers turn blue. Jeremy's mother, who carries the main responsibility for his daily care, believes that his insensate arms are too heavy and “get in his way,” causing the falls. She and Jeremy's father present to the orthopedic clinic at the children's hospital with the request of having both arms amputated. The primary orthopedic surgeon and the orthopedic team disagree with the parents that bilateral upper‐extremity amputation offers any medical benefit, but Jeremy's mother tells the surgeon that, if he will not perform the surgery, her family will find a doctor who will. The surgeon, who feels ethically distressed by the parental insistence on this amputation in such a young child, requests an ethics consultation.
How Long a Life Is Enough Life?
Authors: Callahan Daniel , Gaylin Willard
Published: July 2017

Humans have long been troubled by the prospect of old age and its culmination in death. Whether to rebel against or accept this fate have been wrestled with down through the centuries. But new medical technologies and the growing science of aging have sided with rebellion. We know that aging can be pushed back and improved in its quality. That progress is well under way, but now intensified by many scientists and Silicon Valley entrepreneurs. In 2016, Mark Zuckerberg and Priscilla Chan pledged three billion dollars toward eventually “preventing, curing or managing all diseases.” And some visionaries have made the elimination of death or its indefinite postponement a goal. To put those aspirations in a broader context, it is helpful to keep in mind where population growth and aging trends stand. Apart from any success in the explicit efforts to increase longevity, there will be a steady increase in the number of elderly worldwide—and a much higher percentage of the elderly as part of the overall population. Most of the largest changes will be in developing countries. They will be overburdened by the death of the elderly from expensive chronic diseases—already a vexing problem for affluent countries.
Patients as Rights Holders
Authors: Brännmark Johan
Published: July 2017

Autonomy and consent have been central values in Western moral and political thought for centuries. One way of understanding the bioethical models that started to develop, especially in the 1970s, is that they were about the fusion of a long‐standing professional ethics with the core values underpinning modern political institutions. That there was a need for this kind of fusion is difficult to dispute, especially since the provision of health care has in most developed countries become an ever more important concern of our political institutions, with governments playing a significant role in regulating and facilitating the provision of health care and in many countries even largely organizing it. There is, nevertheless, still room for dispute about how best to achieve this fusion and how to best think about autonomy and consent in a biomedical context.

The simplest model we can have is probably about how being a person is largely about having the capacity of autonomous choice and that the main mode through which we exercise autonomy is by providing informed consent. Yet, liberal democracy's core idea that human beings have a high and equal value is also found in other accounts of the person. The human‐rights framework provides an alternative model for thinking about personhood and about patient care. The human‐rights approach is grounded, not in an account of autonomy (although it has something to say about autonomy), but in an account of the moral and political personhood that people possess merely by being human beings. In this approach, values like dignity and integrity, both highly relevant in a bioethical context, are identified as distinct values rather than being derived from and therefore reduced to respect for autonomous choice. The human‐rights approach can supplement the problematic notion of autonomy that has been central to bioethics by placing this notion in a broader, strongly pluralistic framework.
It's “the End of Sex” As We Know It, and I Feel … a Little Nervous
Authors: King Louise P.
Published: July 2017

Reading Henry Greely's wonderful book, The End of Sex and the Future of Human Reproduction, while riding public transport sparked awkward looks and equally awkward discussions. I thought of removing the dust jacket, yet I was reminded that Greely's stated purpose in writing the book was to spark conversation. The title is, of course, intentionally provocative. Greely does not, in fact, believe that humans will stop having sex for the multitude of reasons that we do already. Quite the contrary; he proposes that sex for reproduction will become a technical endeavor, while sex for pleasure or other purposes beyond reproduction will remain as it is. In a not‐too‐distant future, advances in genomics and assisted reproduction, especially preimplantation genetic diagnosis, will allow us to control the genetic makeup of embryos. To a limited degree, PGD already makes this possible, but what Greely proposes is slightly different. His vision of the future depends on the potential for further advances of today's already fairly complex biotechnology. Greely does an excellent job of making this cutting‐edge science easy to understand.
Impact of Sustained Virologic Response with Direct‐Acting Antiviral Treatment on Mortality in Patients with Advanced Liver Disease
Authors: Backus Lisa I. , Belperio Pamela S. , Shahoumian Troy A. , Mole Larry A.
Published: July 2017

The impact of sustained virologic response (SVR) on mortality after direct‐acting antiviral treatment is not well documented. This study evaluated the impact of direct‐acting antiviral–induced SVR on all‐cause mortality and on incident hepatocellular carcinoma (HCC) in 15,059 hepatitis C virus–infected patients with advanced liver disease defined by a FIB‐4 >3.25. Overall, 1,067 patients did not achieve SVR (no SVR) and 13,992 patients achieved SVR. In a mean follow‐up period of approximately 1.6 years, 195 no SVR patients and 598 SVR patients died. Mortality rates were 12.3 deaths/100 patient years of follow‐up for no SVR patients and 2.6 deaths/100 patient years for SVR patients, a 78.9% reduction (P < 0.001). Among patients without a prior diagnosis of HCC, 140 no SVR patients and 397 SVR patients were diagnosed with incident HCC. HCC rates were 11.5 HCCs/100 patient years for no SVR patients and 1.9 HCCs/100 patient years for SVR patients, an 83.5% reduction (P < 0.001). In multivariable Cox proportional hazard models controlling for baseline demographics, clinical characteristics, and comorbidities, SVR was independently associated with reduced risk of death compared to no SVR (hazard ratio, 0.26; 95% confidence interval, 0.22‐0.31; P < 0.001). A history of decompensated liver disease (hazard ratio, 1.57; 95% confidence interval, 1.34‐1.83; P < 0.001) and decreased albumin (hazard ratio, 2.70 per 1 g/dL decrease; 95% confidence interval, 2.38‐3.12; P < 0.001) were independently associated with increased risk of death. Conclusion: Those achieving SVR after direct‐acting antiviral treatment had significantly lower all‐cause mortality and lower incident HCC rates than those who did not achieve SVR.
L‐ornithine L‐aspartate in bouts of overt hepatic encephalopathy
Authors: Sidhu Sandeep Singh , Sharma Barjesh Chander , Goyal Omesh , Kishore Harsh , Kaur Navpreet
Published: July 2017

High‐quality data on the efficacy of L‐ornithine L‐aspartate (LOLA) in patients with cirrhosis and bouts of overt hepatic encephalopathy (OHE) are missing. We evaluated the efficacy of intravenous LOLA in the reversal of bouts of OHE in patients with cirrhosis. In this prospective, double‐blind, randomized, placebo‐controlled trial conducted at two tertiary care institutes in India, 370 patients with cirrhosis and bouts of OHE were screened. After exclusion, 193 (52.16%) patients were randomized to receive either intravenous infusions of LOLA (n = 98), 30 g daily, or placebo (n = 95) for 5 days. Standard of care treatment (including lactulose and ceftriaxone) was given in both groups. Randomization was done centrally (http://www.sealedenvelope.com/). All study personnel were blinded to the treatment assignment. Fasting venous ammonia levels were estimated daily from 0 to 5 days. Serum tumor necrosis factor‐alpha, interleukins, hemogram, and liver and renal function tests were performed at days 0 and 5. Primary outcome was mental state grade at day 5 of treatment. The grade of OHE was significantly lower in the LOLA group (compared to placebo) on days 1‐4 but not on day 5. The mean time taken for recovery was lower in the LOLA group compared to the placebo group (1.92 ± 0.93 versus 2.50 ± 1.03 days, P = 0.002; 95% confidence interval −0.852 to −0.202). Venous ammonia at day 5 and length of hospital stay were significantly lower in the LOLA group. No significant difference in interleukins was seen between the groups. Conclusion: In patients with bouts of OHE, intravenous LOLA (as an add‐on therapy to lactulose and ceftriaxone) significantly improves the grade of OHE over days 1‐4, but not on day 5, and decreases venous ammonia, time of recovery, and length of hospital stay. (Hepatology 2018;67:700‐710).
The prevalence of DICER1 pathogenic variation in population databases
Authors: Kim Jung , Field Amanda , Schultz Kris Ann P. , Hill D. Ashley , Stewart Douglas R.
Published: July 2017

The DICER1 syndrome is associated with a variety of rare benign and malignant tumors, including pleuropulmonary blastoma (PPB), cystic nephroma (CN) and Sertoli‐Leydig cell tumor (SLCT). The prevalence and penetrance of pathogenic DICER1 variation in the general population is unknown. We examined three publicly‐available germline whole exome sequence datasets: Exome Aggregation Consortium (ExAC), 1,000 Genomes (1,000 G) and the Exome Sequencing Project (ESP). To avoid over‐estimation of pathogenic DICER1 variation from cancer‐associated exomes, we excluded The Cancer Genome Atlas (TCGA) variants from ExAC. All datasets were annotated with snpEff and ANNOVAR and variants were classified into four categories: likely benign (LB), unknown significance (VUS), likely pathogenic (LP), or pathogenic (P). The prevalence of DICER1 P/LP variants was 1:870 to 1:2,529 in ExAC‐nonTCGA (53,105 exomes) estimated by metaSVM and REVEL/CADD, respectively. A more stringent prevalence calculation considering only loss‐of‐function and previously‐published pathogenic variants detected in ExAC‐nonTCGA, yielded a prevalence of 1:10,600. Despite the rarity of most DICER1 syndrome tumors, pathogenic DICER1 variation is more common than expected. If confirmed, these findings may inform future sequencing‐based newborn screening programs for PPB, CN and SLCT, in which early detection improves prognosis.
Substrate specificity in the context of molecular chaperones
Authors: Bose Dipayan , Chakrabarti Abhijit
Published: July 2017

Molecular chaperones are one of the key players in protein biology and as such their structure and mechanism of action have been extensively studied. However the substrate specificity of molecular chaperones has not been well investigated. This review aims to summarize what is known about the substrate specificity and substrate recognition motifs of chaperones so as to better understand what substrate specificity means in the context of molecular chaperones. Available literature shows that the majority of chaperones have broad substrate range and recognize non‐native conformations of proteins depending on recognition of hydrophobic and/or charged patches. Based on these recognition motifs chaperones can select for early, mid or late folding intermediates. Another major contributor to chaperone specificity are the co‐chaperones they interact with as well as the sub‐cellular location they are expressed in and the inducability of their expression. Some chaperones which have only one or a few known substrates are reported. In their case the mode of recognition seems to be specific structural complementarity between chaperone and substrate. It can be concluded that the vast majority of chaperones do not show a high degree of specificity but recognize elements that signal non‐native protein conformation and their substrate range is modulated by the context they function in. However a few chaperones are known that display exquisite specificity of their substrate e.g. mammalian heat shock protein 47 collagen interaction. © 2017 IUBMB Life, 69(9):647–659, 2017
1‐palmitoyl‐2‐linoleoyl‐3‐acetyl‐rac‐glycerol (PLAG) reduces hepatic injury in concanavalin A‐treated mice
Authors: Ko Young E. , Yoon Sun Y. , Ly Sun Y. , Kim Joo H. , Sohn Ki Y. , Kim Jae W.
Published: July 2017

1‐palmitoyl‐2‐linoleoyl‐3‐acetyl‐rac‐glycerol (PLAG), a chemically synthesized monoacetyldiaglyceride, is one of the constituents in Sika deer antlers and has been known traditionally as having immunomodulatory effects. However, the mechanism by which PLAG controls neutrophil migration, which evokes liver injury in the hepatitis animal model, remains largely unknown. This study was designed to evaluate the immunomodulatory effects of PLAG on cytokine secretion and neutrophil migration in vivo and in vitro. Concanavalin A (Con A) induced leukocyte infiltration in the liver and increased plasma cytokine levels. Pretreatment with PLAG reduced the levels of interleukin (IL)‐4, IL‐6, IL‐10, and CXCL2, but maintained interferon (IFN)‐γ levels and modulated neutrophil recruitment toward the liver. Furthermore, the mRNA and protein levels of IL‐4 and CXCL2 in liver tissue were also decreased in the Con A‐treated mice. Liver histology analyses showed that PLAG reduced Con A‐induced hepatic necrosis, which was accompanied by leukocyte infiltration. The in vitro studies revealed that PLAG reduced IL‐4 secretion in Con A stimulated T cell and blocked signal transducer and activator of transcription 6 (STAT6) Con A induced hepatocyte. PLAG attenuated IL‐4 induced activation of atypical protein kinase C (PKC)/STAT6 in hepatocytes and inhibited neutrophil migration toward the liver tissue through suppression of IL‐8/vascular cell adhesion molecule (VCAM) expression. These results suggest that PLAG could mitigate excess neutrophil migration into liver tissue and potentially have a therapeutic effect on immune‐mediated liver injury.
Update to the Global Climate Data package: analysis of empirical bias correction methods in the context of producing very high resolution climate projections
Authors: Mosier Thomas M. , Hill David F. , Sharp Kendra V.
Published: July 2017

While global climate models (GCMs) are useful for simulating climatic responses to perturbations in the Earth's climate system, there are many instances where higher spatial resolution information is necessary. In all instances, interpretation of interpolated or downscaled GCMs must be done cautiously because each method has its own set of assumptions and potential disadvantages. Here, we present an update to the Global Climate Data (GCD) package, which enables the package to efficiently bias correct and interpolate precipitation and air temperature output from GCM simulations to very high spatial resolutions using the delta change method. While the delta change method is relatively simple, it has previously been shown to enhance the physical representation of interpolated climate time‐series compared to directly interpolating the gridded climate time‐series to a higher spatial resolution. The bias correction methods programmed into the GCD package are univariate empirical quantile mapping (QM) and bivariate empirical joint bias correction (JBC). The skill of QM and JBC for improving GCM simulations processed with the delta change method is evaluated through comparing the cumulative distribution functions (CDFs) of the interpolated GCM simulations to the CDFs of Global Historical Climatology Network (GHCN) station observations for three test regions: Oregon (in the USA), the Alps (spanning several countries in Europe), and the Ganges Delta (in India and Bangladesh). We also assess the representation of precipitation and mean temperature joint probability distributions relative to those present in GHCN station observations. Overall, GCM simulations that are bias corrected with QM prior to being input to the delta change method perform best under our analysis.
Advantages of RNA‐seq compared to RNA microarrays for transcriptome profiling of anterior cruciate ligament tears
Authors: Rai Muhammad Farooq , Tycksen Eric D. , Sandell Linda J. , Brophy Robert H.
Published: July 2017

Microarrays and RNA‐seq are at the forefront of high throughput transcriptome analyses. Since these methodologies are based on different principles, there are concerns about the concordance of data between the two techniques. The concordance of RNA‐seq and microarrays for genome‐wide analysis of differential gene expression has not been rigorously assessed in clinically derived ligament tissues. To demonstrate the concordance between RNA‐seq and microarrays and to assess potential benefits of RNA‐seq over microarrays, we assessed differences in transcript expression in anterior cruciate ligament (ACL) tissues based on time‐from‐injury. ACL remnants were collected from patients with an ACL tear at the time of ACL reconstruction. RNA prepared from torn ACL remnants was subjected to Agilent microarrays (N = 24) and RNA‐seq (N = 8). The correlation of biological replicates in RNA‐seq and microarrays data was similar (0.98 vs. 0.97), demonstrating that each platform has high internal reproducibility. Correlations between the RNA‐seq data and the individual microarrays were low, but correlations between the RNA‐seq values and the geometric mean of the microarrays values were moderate. The cross‐platform concordance for differentially expressed transcripts or enriched pathways was linearly correlated (r = 0.64). RNA‐Seq was superior in detecting low abundance transcripts and differentiating biologically critical isoforms. Additional independent validation of transcript expression was undertaken using microfluidic PCR for selected genes. PCR data showed 100% concordance (in expression pattern) with RNA‐seq and microarrays data. These findings demonstrate that RNA‐seq has advantages over microarrays for transcriptome profiling of ligament tissues when available and affordable. Furthermore, these findings are likely transferable to other musculoskeletal tissues where tissue collection is challenging and cells are in low abundance. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:484–497, 2018.
Development of a cruise motivation scale for emerging markets in Asia
Authors: Hsu Cathy H.C. , Li Minglong
Published: July 2017

Cruise travel has attracted the attention of researchers because of its rapid development. However, the literature lacks a reliable and valid measurement tool for constructing cruise motivation. The only available scale developed in the North American context, where the cruise industry is considerably mature, may be inapplicable to emerging markets due to cultural and experiential differences. To address this research gap, a measurement scale for cruise motivation in emerging markets, with Mainland China and Hong Kong as samples, was developed by following rigorous procedures that used both qualitative and quantitative methods. This study offers both academic and operational implications.
Phosphorus and nitrogen starvation reveal life‐cycle specific responses in the metabolome of Emiliania huxleyi (Haptophyta)
Authors: Wördenweber Robin , Rokitta Sebastian D. , Heidenreich Elena , Corona Katrin , Kirschhöfer Frank , Fahl Kirsten , Klocke Jessica L. , Kottke Tilman , Brenner‐Weiß Gerald , Rost Björn , Mussgnug Jan H. , Kruse Olaf
Published: July 2017

The coccolithophore Emiliania huxleyi is a microalga with biogeochemical and biotechnological relevance, due to its high abundance in the ocean and its ability to form intricate calcium carbonate structures. Depletion of macronutrients in oceanic waters is very common and will likely enhance with advancing climate change. We present the first comprehensive metabolome study analyzing the effect of phosphorus (P) and nitrogen (N) starvation on the diploid and haploid life‐cycle stage, applying various metabolome analysis methods to gain new insights in intracellular mechanisms to cope with nutrient starvation. P‐starvation led to an accumulation of many generic and especially N‐rich metabolites, including lipids, osmolytes, and pigments. This suggests that P‐starvation primarily arrests cell‐cycling due to lacking P for nucleic acid synthesis, but that enzymatic functionality is widely preserved. Also, the de‐epoxidation ratio of the xanthophyll cycle was upregulated in the diploid stage under P‐starvation, indicating increased nonphotochemical quenching, a response typically observed under high light stress. In contrast, N‐starvation resulted in a decrease of most central metabolites, also P‐containing ones, especially in the diploid stage, indicating that most enzymatic functionality ceased. The two investigated nutrient starvation conditions caused significantly different responses, contrary to previous assumptions derived from transcriptomic studies. Data highlight that instantaneous biochemical flux is a more dominant driver of the metabolome than the transcriptomically rearranged pathway patterns. Due to the fundamental nature of the observed responses it may be speculated that microalgae with similar nutrient requirements can cope better with P‐starvation than with N‐starvation.
Mixed mode analysis and measurement in overmoded circular waveguide system
Authors: Zhao Xuelong , Yuan Chengwei , Liu Lie , Peng Shengren , Zhang Qiang , Zhou Hongyu
Published: July 2017

In high‐power microwave (HPM) area, increasing the cross‐sectional dimension makes the device work in overmoded state, is an efficient way to improve the device's power handling capacity. However, the high order mixed modes may decrease the efficiency of the microwave output. Therefore, it is necessary to study the mixed modes in overmoded waveguides. Mixed modes analysis in circular waveguide system will be discussed in this paper, and the measurement results are agreed well with the theoretical and simulation results.
Dual band gysel power divider with high power dividing ratio
Authors: Gai Chao , Jiao Yong‐Chang , Weng Zi‐Bin , Zhao Gang , Zhao Yu‐Long
Published: July 2017

A dual band Gysel power divider (PD) with high power dividing ratio based on the defected ground structure (DGS) is presented. Three open ended stubs are added to the conventional Gysel PD to achieve dual band property. Closed‐form design formulas are derived by using the circuit theory and the transmission matrix theory. For verification, a prototype operating at 0.9 and 1.8 GHz with the power dividing ratio of 10 is fabricated and tested. The measured results show a reasonable agreement with the simulated ones.
A miniaturized‐element bandpass frequency selective surface using meander line geometry
Authors: Varuna A. B. , Ghosh Saptarshi , Srivastava Kumar Vaibhav
Published: July 2017

In this paper, a low‐profile miniaturized‐element frequency selective surface (FSS) is presented numerically as well as experimentally. The proposed design consists of a meandered pattern printed on both sides of an ultra‐thin (0.0005λ0) FR‐4 substrate, which exhibits a bandpass characteristic at 750 MHz having unit cell dimensions of 0.017λ0 × 0.017λ0. The structure, being asymmetric in nature, selectively realizes bandpass operation for a specific polarization, whereas transmits incident wave for other polarizations. The novelties of the design lie in its miniaturization performance as well as ultra‐thin profile as compared with the earlier reported structures. The proposed structure has further been analyzed through deriving equivalent circuit models and parametric variations. Finally, a prototype of the FSS is fabricated and the measured response is in good agreement with the simulated result under normal incidence.
Dual band bandpass filter using meander split loop resonator
Authors: Li Xiaokun , Zhang Yonghong , Xie Jinxiong , Zhang Xingyu , Tian Yin , Fan Yong
Published: July 2017

Based on meander split loop resonator (MSLR), dual band filter with wide bandwidth, low insertion loss and compactness is investigated and fabricated. Embedded spiral coupled line (ESCL) is added not only to enhance coupling between two split stubs, but to adjust transmission zeros (TZs) and form dual band response. Through transformation among ABCD‐matrix, Y‐matrix, and S‐matrix, TZs of proposed filter can be analyzed. Utilizing direct connection of feed line and MSLR, low insertion loss is achieved.
UWB harmonic‐suppressed miniaturized ring bandpass filter using artificial transmission lines
Authors: Sim Kyung‐Sub , Hwang Hee‐Yong
Published: July 2017

This letter presents a whole UWB band suppressed ring resonator bandpass filter with small LUCs (Lowpass filter unit cells) [Lee W‐K, Hwang H‐Y. J Electromagn Eng Sci. 2014;14:387–392.] based on artificial transmission lines [Martin F. Artificial Transmission Lines for RF and Microwave Applications. 1st ed. New York: Wiley; 2015]. Two LUCs are used as building blocks for miniaturization and harmonic suppression of the ring resonator of the filter. Design equations for proper characteristic impedances of the ring and for proper stopband transmission zeros of the LUCs are newly presented. Fabricated filter shows insertion loss of 2.3 dB at center frequency of 2.55 GHz, fractional bandwidth of 2.5%, and good harmonic suppression about 20 dB in whole ultra‐wide band, which agreed well with the simulation results. The ring area of the proposed bandpass filter has 36% of that of the conventional one.
Investigation of the large‐gap‐ground rectangular patch antenna
Authors: Wang Yiying , Lu Yinghua
Published: July 2017

The wearable antenna is being investigated, however, it faces a challenge in the special situation where the threads will be broken abruptly because of the aging or be cut. In this article, this satiation is imitated by cutting off part of the ground of the rectangular conventional patch antenna, which is excited by the coaxial cable, because it can be a textile one easily if the material is replaced by the fabric. Here, the ground plane is entirely sliced for a fixed area along the E‐plane direction and the sliced structure is symmetrical on the width direction. And the conventional patch antenna is designed as a benchmark to be compared with the gap‐ground antennas. Their corresponding results show the cross‐polarizations of the E‐plane increase and the resonances shift to the lower frequency, but the back radiation is affected little because of the coupling opposite currents on the strips. Also, the antenna has dual‐band characteristic if the gap ratio of the gap to the original solid ground plane is <1:4, and the biggest sliced gap ratio up to 3:4 so that the antenna has a large‐gap ground. Besides, the pattern of E‐plane has a tilt while that of H‐plane hasn't.
CPW feed dual band and wideband antennas using crescent shape and T‐shape stub for Wi‐Fi and WiMAX application
Authors: Dwivedi Ravi Prakash , Kommuri Usha Kiran
Published: July 2017

This letter presents design of novel annular ring crescent shape dual band and wideband antennas using T‐shape stub for worldwide interoperability for microwave access (Wi‐MAX) and wireless local area network (WLAN). These antennas are designed based on annular ring antenna and CPW feed. Dual band ring antenna with truncated ground plane provides a resonance at 3.5 GHz and addition of crescent shape with tuning of T‐shape stub provides a second resonance at 5.8 GHz. Ground plane shape is extremely significant for impedance matching. Wide band ring antenna with crescent shape and modified T‐shape stub exhibits bandwidth of 6.35 GHz from 4.75 to 11.1 GHz, further study shows that compactness of the antenna makes it suitable for active integrated antenna (AIA) application. Both dual band and wideband compact antennas are fabricated on FR4 substrate with the compact size of
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A miniaturized triple band‐notched UWB antenna
Authors: Arshed Talha , Tahir Farooq A.
Published: July 2017

In this study, a compact microstrip‐fed ultra‐wideband (UWB) monopole antenna with triple band‐notched characteristics is presented. UWB bandwidth is achieved through tapering of both the radiating element and the transmission line. A single parasitic microstrip resonator on the backside of the radiator is introduced to realize filtering at WiMAX (3.5 GHz) and WLAN (5.25, 5.775) bands. The microstrip resonator having dimensions of 8.2 mm × 8 mm is made up of three L‐shaped strips inside a C‐shaped strip. The overall size of the antenna is very compact 12 × 18 mm2. The antenna provides sharp cut‐offs in the notched‐bands to conserve all the useful frequencies within the ultra‐wideband. Measured impedance‐bandwidth of the antenna is 3.1–11.5 GHz for voltage standing wave ratio (VSWR) <2 except for the notched‐bands 3.4–3.6 GHz, 5.15–5.39 GHz, and 5.75–5.96 GHz. The antenna is also analyzed for far‐field characteristics and a good agreement is found between simulated and measured results.
A novel FSS for gain enhancement of printed antennas in UWB frequency spectrum
Authors: Tahir Farooq A. , Arshad Talha , Ullah Sadiq , Flint James A.
Published: July 2017

This paper presents a novel compact unilayer frequency selective surface (FSS) for ultra‐wideband (UWB) applications particularly for gain enhancement of printed antennas. The proposed FSS unit cell consists of simple metallic patterns printed on both sides of 14 mm × 14 mm FR4 substrate. The proposed FSS has very low transmission co‐efficient and linearly decreasing reflection phase over the bandwidth of 9 GHz in 3–12 GHz range, which makes it suitable candidate to provide in‐phase reflection for UWB antennas. For the validation of gain‐enhancement capability, the FSS is paired with a general monopole UWB antenna demonstrating an average gain improvement of 4 dB. The antenna composite has a maximum gain of 8.9 dBi.
Design and characterization of a diamond‐shaped monopole antenna
Authors: Maricar Mohamed Ismaeel , Bahar Ahmad , Greedy Steve , Smartt Chris , Phang Sendy , Gradoni Gabriele , Cross Richard , Creagh Stephen C. , Tanner Gregor , Thomas David W. P.
Published: July 2017

We report a new planar antenna design in the shape of a diamond. The performance of the antenna design is initially obtained through simulation, then fabricated, and its performance evaluated through experiment. Experimental characterization of the diamond‐shaped monopole antenna shows good agreement with simulation. In comparison with a simple monopole antenna, our diamond‐shaped monopole antenna features smaller geometric footprint and displays a higher bandwidth at millimeteric wave frequencies.
Multiband plasmonic nanoantenna structure for infrared energy harvesting based on electron field emission rectification
Authors: Chekini A. , Sheikhaei S. , Neshat M.
Published: July 2017

In this article, a multiband, planar, direct energy rectification, and dual polarized infrared plasmonic nanoantenna is presented and numerically simulated using finite element method (FEM). Broadband characteristics are highly suitable for energy harvesting applications. The proposed nanoantenna structure comprises cross bowtie aluminum structures deposited on the silicon dioxide (SiO2) substrate. In the proposed device, incoming thermal electromagnetic energy is first enhanced by micro‐lenses through focusing the thermal energy onto the nanoantenna. Then, further enhancement is achieved using several nanoantennas, each with different resonance length, to achieve enough electrical field for electron field emission from sharp metallic tips in their gaps. Each nanoantenna resonates in the proper wavelength, electrical field is enhanced in the gap, and finally, a total current is generated from electron field emissions. The calculated current, based on Fowler‐Nordheim theory, matches well with the simulation results. The total current of the proposed nanostructure is superposition of the produced current of each nanoantenna. To our best knowledge, this is the first report on a multiband nanostructure for energy harvesting. As a typical implementation, a structure is designed for energy absorption in the mid infrared wavelengths, 1‐4 µm.
Experimental realization of micromachined terahertz multistepped quasi‐diagonal horn antenna
Authors: Zhao Pengfei , Liu Yong , lv Xin
Published: July 2017

A design of a terahertz (THz) quasi‐diagonal horn antenna with multistepped isosceles trapezoid slots based on the micromachining technology is presented. The radiation patterns are designed to be with high Gaussian coupling efficiency. The radiation patterns, VSWR, gain are measured, and good agreements with the simulated results are found.
Diffuse bifurcations engraving diverse shear bands in granular materials
Authors: Yamakawa Yuki , Ikeda Kiyohiro , Saiki Isao , Desrues Jacques , Tanaka Reiko J.
Published: July 2017

Shear bands with characteristic spatial patterns observed in an experiment for a cubic or parallelepiped specimen of dry dense sand were simulated by numerical bifurcation analysis using the Cam‐clay plasticity model. By incorporating the subloading surface concept into the plasticity model, the model became capable of reproducing hardening/softening and contractive/dilative behavior observed in the experiment. The model was reformulated to be compatible with the multiplicative hyperelasto‐plasticity for finite strains. This enhanced constitutive model was implemented into a finite‐element code reinforced by a stress updating algorithm based on the return‐mapping scheme, and by an efficient numerical procedure to compute critical eigenvectors of elastoplastic tangent stiffness matrix at bifurcation points. The emergence of diamond‐ and column‐like diffuse bifurcation modes breaking uniformity of the materials, followed by the evolution of shear bands through strain localization, was observed in the analysis. In the bifurcation analysis of plane strain compression test, unexpected bifurcation modes, which broke out‐of‐plane uniformity and led to 3‐dimensional diamond‐like patterns, were detected. Diffuse bifurcations, which were difficult to observe by experiments, have thus been found as a catalyst creating diverse shear band patterns.
Synthesis of nitrogen doped activated carbon/polyaniline material for CO2 adsorption
Authors: Peyravi Majid
Published: July 2017

The equilibrium adsorption isotherms of carbon dioxide and nitrogen on the nitrogen doped activated carbon (NAC) prepared by the chemical activation of a pine cone‐based char/polyaniline composite were measured using a volumetric technique. CO2 and N2 adsorption experiments were done at three different temperatures (298, 308, and 318 K) and pressures up to 16 bar, and correlated with the Langmuir, Freundlich, and Sips models. The Sips isotherm model presented the best fit to the experimental data. The N‐doped adsorbent showed CO2 and N2 adsorption capacity of 3.96 mmol·g−1 and 0.86 mmol·g−1, respectively, at 298 K and 1 bar. The selectivity predicted by ideal adsorbed solution theory (IAST) model was achieved 47.17 for NAC at 1 bar and yN2 = 0.85 which is a composition similar to flue gas. The results showed that NAC adsorbent has a high CO2‐over‐N2 selectivity in a binary mixture. The relatively fast sorption rate of CO2 on NAC compared to N2 indicates the stronger affinity between CO2 and amine groups. The isosteric heat of adsorption of CO2 by the NAC demonstrated the physico‐chemical adsorption of CO2 on the adsorbent surface. These data showed that prepared NAC could be successfully applied in separation of CO2 from N2.
Connector type‐controlled mesophase structures in poly(propyl ether imine) dendritic liquid crystals of identical dendrimer generations
Authors: Kumar Prabhat , Shankar Rao D. S. , Krishna Prasad S. , Jayaraman Narayanaswamy
Published: July 2017

Poly(propyl ether imine) (PETIM) dendrimers of one to three generations are used as dendritic cores to identify the influence of varying connector types that connect the dendritic core with peripheral mesogens on the emerging liquid crystalline (LC) properties. The LC properties vary in these dendritic liquid crystals, even when the dendrimer generations and thus the number of peripheral mesogenic moieties remain identical. PETIM dendrimer generations one to three, ester and amide connectors varying with succinates, phthalates, and succinamides, are studied herein. Cholesteryl moieties are installed at the peripheries through the above connectors to induce mesogenic properties. These modified dendritic liquid crystals reveal a layered mesophase structure in most ester and amide connector‐derivatives, whereas a third‐generation phthalate ester dendrimer favors a rectangular columnar mesophase structure. A transition from layered to a rectangular columnar structure results by a mere change in the connector varying between a succinate or succinamide or phthalate, within one particular dendrimer generation and without altering the underlying dendrimer core or the number of mesogenic moieties. The study demonstrates that in dendritic liquid crystals with essentially identical chemical constitutions, a change in the connector type connecting the mesogen with the dendrimer core is sufficient to change the mesophase structures. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3665–3678
Poly(N‐vinylpyrrolidone)–polydimethylsiloxane amphiphilic ABA triblock copolymers
Authors: Pavlović Dražen , Lou Qin , Linhardt Jeffrey G. , Künzler Jay F. , Shipp Devon A.
Published: July 2017

Triblock copolymers of N‐vinylpyrrolidone (NVP) and polydimethylsiloxane (PDMS) were synthesized by reversible addition‐fragmentation chain transfer (RAFT) polymerization using two different types of difunctional telechelic PDMS‐based dixanthate macroinitiators. The incorporation of PDMS into the triblock copolymers was evidenced by 1H NMR spectroscopy and varied between 4 mol % and as high as 20 mol %, dependent on reaction time and monomer conversion. The copolymer homogeneity was characterized in terms of molecular weight distribution determined by GPC to estimate the level of control over the chain length. Monomodal molecular weight distributions were observed, and 1H NMR spectroscopy indicated the copolymers had number average molecular weights (Mn) ranging between 28,000 and 160,000 g/mol. In addition, thin film phase separation and critical micelle concentrations for these copolymers were analyzed via transmission electron microscopy and surface tension measurements, respectively. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3387–3394
One pot synthesis of bimodal UHMWPE/HDPE in‐reactor blends with Cr/V bimetallic catalysts
Authors: Jin Yulong , Zhao Ning , Cheng Ruihua , He Xuelian , Liu Zhen , Dong Dalin , Bin Yuezhen , Chen Xiaowei , Li Liangbin , Liu Boping
Published: July 2017

Bimodal ultra‐high‐molecular‐weight polyethylene (UHMWPE)/high‐density polyethylene (HDPE) in‐reactor blends (IRBs) are produced by the bimetallic catalysts, which are synthesized through co‐supporting silylchromate and vanadium‐oxide‐based catalysts on silica or alumina, zirconia and titania‐modified silica. After support modification, the activities of the catalysts for ethylene polymerization are substantially enhanced. The IRBs produced by the modified catalysts also contain more UHMWPE and low‐molecular‐weight polyethylene (LMWPE) fractions, and have much broader molecular weight distribution (MWD). The homogeneous nature of the IRBs is preliminarily confirmed by the differential scanning calorimetry melting curves, showing unique melting peak in both nascent and recrystallized states. The rheological results reflect that the viscosity of the IRBs is reduced more or less when compared with UHMWPE. The distinct elastic dominance of the IRBs is also observed, implying the UHMWPE characteristics in the IRBs. In addition, the intimate mixing of the IRBs is further verified by the similar slopes of Han curves for the polyethylene (PE) samples. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3404–3412
Polyimides from an asymmetric hydroxyl‐containing aliphatic‐aromatic diamine synthesized via henry reaction
Authors: Wang Zhiang , Guo Liying , Han Songyu , Qi Haixia , Cheng Yusheng , Liu Feng
Published: July 2017

An aliphatic amino and an aliphatic hydroxyl group have been incorporated via Henry reaction highly efficiently toward the synthesis of a novel asymmetric aliphatic–aromatic diamine 2‐amino‐1‐[4‐(5‐aminopyridyloxy)phenyl]‐1‐ethanol (AAPyPhE) in three steps. AAPyPhE shows good copolymerization reactivity with 4,4′‐oxydianiline (ODA) toward different aromatic dianhydrides, especially 4,4′‐oxydiphthalic anhydride (ODPA). TGA measurement and mechanical test results show that all polymers maintain the inherent thermal performance and tensile properties, while the glass transition temperatures (Tg's) by DMA show moderate decrease ranging from 185.5 to 253.3 °C due to the presence of aliphatic segments. The introduction of AAPyPhE is found to improve the solubility of the polymers, and the polymer films' optical transparency with decreased cutoff wavelength (λ0) ranging from 328 to 370 nm. Comparative studies reveal that the pendent aliphatic hydroxyls in the polymer chains would lead to interchain cross‐linking via condensation and secondary weak cross‐linking by hydrogen bond depending on different loading of AAPyPhE, which result in a fluctuation of hydrophilic–hydrophobic properties, DMA tanδand dielectric constant of the copolymer films. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2017,55, 3413–3423
Role of polythiophenes as electroactive materials
Authors: Pathiranage Taniya M. S. K. , Dissanayake Dushanthi S. , Niermann Crystal N. , Ren Yixin , Biewer Michael C. , Stefan Mihaela C.
Published: July 2017

Semiconducting polythiophenes display electroactive properties which make them excellent candidates for applications as electroactive materials. Ability to undergo doping and to switch between different oxidation states allow tuning the chemical and physical properties of polythiophenes. Furthermore, the ability to integrate polythiophenes into copolymers, hybrid composites with metals and inorganic materials make them useful in electronic and biomedical applications. The capability to vary the properties of the final material with low production cost and high processability into thin films makes polythiophenes desirable materials for many applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3327–3346
Synthesis and characterization of brush diblock and triblock copolymers bearing polynorbornene backbone and poly(l‐lactide) and/or poly(hexyl isocyanate) side chains by a combination of coordination and ring opening metathesis polymerization
Authors: Choinopoulos Ioannis , Patias George , Koinis Spyros , Pitsikalis Marinos
Published: July 2017

We report the synthesis of poly(l‐lactide) and poly(hexyl isocyanate) macromonomers using bischloro‐η5‐cyclopentadienyl(bicyclo[2.2.1]‐hept‐5‐en‐2‐oxy) Titanium (IV), [CpTiCl2(O‐NBE)]. These macromonomers bearing a norbornene end group were polymerized towards brush copolymers employing Grubbs' first generation catalyst. Brush copolymers consisting of blocks with different side chains were synthesized. The polymers were characterized by Size Exclusion Chromatography, Nuclear Magnetic Resonance, and their thermal properties were investigated by Thermogravimetric Analysis, and Differential Scanning Calorimetry analysis. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3455–3465
Experimental Study on Dynamic Combustion Characteristics of Aluminum Particles
Authors: Zhou Yunan , Liu Jianzhong , Wang Jianru , Xv Tuanwei , Wang Jiahao , Zhou Junhu , Cen Kefa
Published: July 2017

Studying the combustion characteristics and properties of the condensed phase products of aluminum particles is significant for the application of aluminum‐based propellants. The microstructure, particle size distribution, specific surface area and metallic Al contents of three different samples were analyzed by scanning electron microscopy, laser particle size analyzer, nitrogen adsorption and inductively coupled plasma atomic emission spectroscopy. The thermal oxidation characteristics of the samples were also studied by a thermal analyzer. A dynamic combustion test system was used to study the combustion process in motion and the properties of the products. The results show that as the activation energy of the sample decreases, the initial reaction temperature decreases during the thermal analysis. Moreover, the thermal oxidation degree increases with the decrease in particle size. In the dynamic combustion process, the combustion efficiency of the sample was calculated by using the temperature distribution in the combustion process, and the calculated results were in good agreement with the results of ICP measurements. With the increase in the particle size of the samples, the heat release was reduced, and the agglomerationand oxidation degree of the condensed phase products were also decreased. By increasing the feeding amount, the combustion temperature and the combustion efficiency would increase. The reaction mechanism in the dynamic furnace involves not only the diffusion reaction, but also the melt‐dispersion reaction. The initial reaction temperature of sample A was between 500∼600 °C, the combustion temperature was between 900∼1000 °C, the ignition delay time was around 270 ms, and the reaction time was about 0.6s.