bluuebunny/crossref_metadata_2025 huggingface dataset:
Temporally dependent pollinator competition and facilitation with mass flowering crops affects yield in co-blooming crops
Authors: Grab Heather , Blitzer Eleanor J. , Danforth Bryan , Loeb Greg , Poveda Katja
Published: March 2017

One of the greatest challenges in sustainable agricultural production is managing ecosystem services, such as pollination, in ways that maximize crop yields. Most efforts to increase services by wild pollinators focus on management of natural habitats surrounding farms or non-crop habitats within farms. However, mass flowering crops create resource pulses that may be important determinants of pollinator dynamics. Mass bloom attracts pollinators and it is unclear how this affects the pollination and yields of other co-blooming crops. We investigated the effects of mass flowering apple on the pollinator community and yield of co-blooming strawberry on farms spanning a gradient in cover of apple orchards in the landscape. The effect of mass flowering apple on strawberry was dependent on the stage of apple bloom. During early and peak apple bloom, pollinator abundance and yield were reduced in landscapes with high cover of apple orchards. Following peak apple bloom, pollinator abundance was greater on farms with high apple cover and corresponded with increased yields on these farms. Spatial and temporal overlap between mass flowering and co-blooming crops alters the strength and direction of these dynamics and suggests that yields can be optimized by designing agricultural systems that avoid competition while maximizing facilitation.
C9ORF135 encodes a membrane protein whose expression is related to pluripotency in human embryonic stem cells
Authors: Zhou Shixin , Liu Yinan , Ma Yumin , Zhang Xiaoyan , Li Yang , Wen Jinhua
Published: March 2017

Human embryonic stem cells (hESCs) are a unique population of cells defined by their capacity for self-renewal and pluripotency. Here, we identified a previously uncharacterized gene in hESCs, C9ORF135, which is sharply downregulated during gastrulation and gametogenesis, along with the pluripotency factors OCT4, SOX2, and NANOG. Human ESCs express two C9ORF135 isoforms, the longer of which encodes a membrane-associated protein, as determined by immunostaining and western blotting of fractionated cell lysates. Moreover, the results of chromatin immunoprecipitation (ChIP), mass spectrometry (MS), and co-immunoprecipitation (co-IP) analyses demonstrated that C9ORF135 expression is regulated by OCT4 and SOX2 and that C9ORF135 interacts with non-muscle myosin IIA and myosin IIB. Collectively, these data indicated that C9ORF135 encodes a membrane-associated protein that may serve as a surface marker for undifferentiated hESCs.
Members of Gammaproteobacteria as indicator species of healthy banana plants on Fusarium wilt-infested fields in Central America
Authors: Köberl Martina , Dita Miguel , Martinuz Alfonso , Staver Charles , Berg Gabriele
Published: March 2017

Culminating in the 1950’s, bananas, the world’s most extensive perennial monoculture, suffered one of the most devastating disease epidemics in history. In Latin America and the Caribbean, Fusarium wilt (FW) caused by the soil-borne fungus Fusarium oxysporum f. sp. cubense (FOC), forced the abandonment of the Gros Michel-based export banana industry. Comparative microbiome analyses performed between healthy and diseased Gros Michel plants on FW-infested farms in Nicaragua and Costa Rica revealed significant shifts in the gammaproteobacterial microbiome. Although we found substantial differences in the banana microbiome between both countries and a higher impact of FOC on farms in Costa Rica than in Nicaragua, the composition especially in the endophytic microhabitats was similar and the general microbiome response to FW followed similar rules. Gammaproteobacterial diversity and community members were identified as potential health indicators. Healthy plants revealed an increase in potentially plant-beneficial Pseudomonas and Stenotrophomonas, while diseased plants showed a preferential occurrence of Enterobacteriaceae known for their plant-degrading capacity. Significantly higher microbial rhizosphere diversity found in healthy plants could be indicative of pathogen suppression events preventing or minimizing disease expression. This first study examining banana microbiome shifts caused by FW under natural field conditions opens new perspectives for its biological control.
MAOA rs1137070 and heroin addiction interactively alter gray matter volume of the salience network
Authors: Sun Yan , Liu Linwen , Feng Jiajia , Yue Weihua , Lu Lin , Fan Yong , Shi Jie
Published: March 2017

The rs1137070 polymorphism of monoamine oxidase A (MAOA) is associated with alcoholism and smoking behavior. However, the association between rs1137070 and heroin addiction remains unclear. In this study, we examined the allelic distribution of rs1137070 in 1,035 heroin abusers and 2,553 healthy controls and investigated the interactive effects of rs1137070 and heroin addiction on gray matter volume (GMV) based on 78 heroin abusers and 79 healthy controls. The C allele frequency of rs1137070 was significantly higher in heroin abusers. Heroin addiction and the rs1137070 variant interactively altered measures of GMV in the anterior cingulate cortex, orbital frontal cortex, temporal pole, and insula, which were correlated with cognitive function. Heroin abusers with the C allele had lower measures of GMV in these regions than the healthy controls with the same allele, whereas those with the T allele displayed a different trend. The altered brain regions were connected with white matter tracts, yielding a structural network that partially overlapped with the salience network. These findings suggest that the low activity-related C allele of MAOA rs1137070 is associated with an increase in the sensitivity to heroin addiction and the damaging effects of heroin abuse on cognition and the salience network.
Copy number variation profile in the placental and parental genomes of recurrent pregnancy loss families
Authors: Kasak Laura , Rull Kristiina , Sõber Siim , Laan Maris
Published: March 2017

We have previously shown an extensive load of somatic copy number variations (CNVs) in the human placental genome with the highest fraction detected in normal term pregnancies. Hereby, we hypothesized that insufficient promotion of CNVs may impair placental development and lead to recurrent pregnancy loss (RPL). RPL affects ~3% of couples aiming at childbirth and idiopathic RPL represents ~50% of cases. We analysed placental and parental CNV profiles of idiopathic RPL trios (mother-father-placenta) and duos (mother-placenta). Consistent with the hypothesis, the placental genomes of RPL cases exhibited 2-fold less CNVs compared to uncomplicated 1st trimester pregnancies (P = 0.02). This difference mainly arose from lower number of duplications. Overall, 1st trimester control placentas shared only 5.3% of identified CNV regions with RPL cases, whereas the respective fraction with term placentas was 35.1% (P = 1.1 × 10−9). Disruption of the genes NUP98 (embryonic stem cell development) and MTRR (folate metabolism) was detected exclusively in RPL placentas, potentially indicative to novel loci implicated in RPL. Interestingly, genes with higher overall expression were prone to deletions (>3-fold higher median expression compared to genes unaffected by CNVs, P = 6.69 × 10−20). Additionally, large pericentromeric and subtelomeric CNVs in parental genomes emerged as a risk factor for RPL.
Large Electrocaloric Effect in Relaxor Ferroelectric and Antiferroelectric Lanthanum Doped Lead Zirconate Titanate Ceramics
Authors: Lu Biao , Li Peilian , Tang Zhenhua , Yao Yingbang , Gao Xingsen , Kleemann Wolfgang , Lu Sheng-Guo
Published: March 2017

Both relaxor ferroelectric and antiferroelectric materials can individually demonstrate large electrocaloric effects (ECE). However, in order to further enhance the ECE it is crucial to find a material system, which can exhibit simultaneously both relaxor ferroelectric and antiferroelectric properties, or easily convert from one into another in terms of the compositional tailoring. Here we report on a system, in which the structure can readily change from antiferroelectric into relaxor ferroelectric and vice versa. To this end relaxor ferroelectric Pb0.89La0.11(Zr0.7Ti0.3)0.9725O3 and antiferroelectric Pb0.93La0.07(Zr0.82Ti0.18)0.9825O3 ceramics were designed near the antiferroelectric-ferroelectric phase boundary line in the La2O3-PbZrO3-PbTiO3 phase diagram. Conventional solid state reaction processing was used to prepare the two compositions. The ECE properties were deduced from Maxwell relations and Landau-Ginzburg-Devonshire (LGD) phenomenological theory, respectively, and also directly controlled by a computer and measured by thermometry. Large electrocaloric efficiencies were obtained and comparable with the results calculated via the phenomenological theory. Results show great potential in achieving large cooling power as refrigerants.
Epigenome mapping highlights chromatin-mediated gene regulation in the protozoan parasite Trichomonas vaginalis
Authors: Song Min-Ji , Kim Mikyoung , Choi Yeeun , Yi Myung-hee , Kim Juri , Park Soon-Jung , Yong Tai-Soon , Kim Hyoung-Pyo
Published: March 2017

Trichomonas vaginalis is an extracellular flagellated protozoan parasite that causes trichomoniasis, one of the most common non-viral sexually transmitted diseases. To survive and to maintain infection, T. vaginalis adapts to a hostile host environment by regulating gene expression. However, the mechanisms of transcriptional regulation are poorly understood for this parasite. Histone modification has a marked effect on chromatin structure and directs the recruitment of transcriptional machinery, thereby regulating essential cellular processes. In this study, we aimed to outline modes of chromatin-mediated gene regulation in T. vaginalis. Inhibition of histone deacetylase (HDAC) alters global transcriptional responses and induces hyperacetylation of histones and hypermethylation of H3K4. Analysis of the genome of T. vaginalis revealed that a number of enzymes regulate histone modification, suggesting that epigenetic mechanisms are important to controlling gene expression in this organism. Additionally, we describe the genome-wide localization of two histone H3 modifications (H3K4me3 and H3K27Ac), which we found to be positively associated with active gene expression in both steady and dynamic transcriptional states. These results provide the first direct evidence that histone modifications play an essential role in transcriptional regulation of T. vaginalis, and may help guide future epigenetic research into therapeutic intervention strategies against this parasite.
Impact of molecular subtypes on metastatic breast cancer patients: a SEER population-based study
Authors: Gong Yue , Liu Yi-Rong , Ji Peng , Hu Xin , Shao Zhi-Ming
Published: March 2017

To investigate the significance and impact of molecular subtyping stratification on metastatic breast cancer patients, we identified 159,344 female breast cancer patients in the Surveillance, Epidemiology and End Results (SEER) database with known hormone receptor (HoR) and human epidermal growth factor receptor 2 (HER2) status. 4.8% of patients were identified as having stage IV disease, and were more likely to be HER2+/HoR−, HER2+/HoR+, or HER2−/HoR−. Stage IV breast cancer patients with a HER2+/HoR+ status exhibited the highest median overall survival (OS) (44.0 months) and those with a HER2−/HoR− status exhibited the lowest median OS (13.0 months). Patients with a HER2−/HoR+ status had more bone metastasis, whereas patients with a HER2+/HoR− status had an increased incidence of liver metastasis. Brain and lung metastasis were more likely to occur in women with a HER2−/HoR− status. The multivariable analysis revealed a significant interaction between single metastasis and molecular subtype. No matter which molecular subtype, women who did not undergo primary tumour surgery had worse survival than those who experienced primary tumour surgery. Collectively, our findings advanced the understanding that molecular subtype might lead to more tailored and effective therapies in metastatic breast cancer patients.
A vacuum ultraviolet laser pulsed field ionization-photoion study of methane (CH4): determination of the appearance energy of methylium from methane with unprecedented precision and the resulting impact on the bond dissociation energies of CH4and CH4+
Authors: Chang Yih-Chung , Xiong Bo , Bross David H. , Ruscic Branko , Ng C. Y.
Published: March 2017

High-resolution VUV laser PFI-PI detection method for the study of quantum-state-selected unimolecular ion dissociation.
Protic ammonium carboxylate ionic liquids: insight into structure, dynamics and thermophysical properties by alkyl group functionalization
Authors: Reddy Th. Dhileep N. , Mallik Bhabani S.
Published: March 2017

This study is aimed at characterising the structure, dynamics and thermophysical properties of five alkylammonium carboxylate ionic liquids (ILs) from classical molecular dynamics simulations.
A novel wide-spectrum response hexagonal YFeO3 photoanode for solar water splitting
Authors: Guo Yongsheng , Zhang Ningsi , Huang Huiting , Li Zhaosheng , Zou Zhigang
Published: March 2017

A novel hexagonal YFeO3 photoanode with wide-spectrum response, exhibiting high theoretical solar-to-hydrogen efficiency (approximately 20%).
Quantum crystallography
Authors: Grabowsky Simon , Genoni Alessandro , Bürgi Hans-Beat
Published: March 2017

Quantum crystallography combines quantum chemistry and experimental diffraction or scattering to provide both enhanced wavefunctions and charge densities.
Ca2+and Ga3+doped LaMnO3perovskite as a highly efficient and stable catalyst for two-step thermochemical water splitting
Authors: Wang Lulu , Al-Mamun Mohammad , Zhong Yu Lin , Jiang Lixue , Liu Porun , Wang Yun , Yang Hua Gui , Zhao Huijun
Published: March 2017

High performance and stable catalysts for two-step thermochemical water splitting are key to synthesising direct fuels in the form of H2or liquid hydrocarbon fuels by the Fischer–Tropsch process.
Eu2+–Eu3+ valence transition in double, Eu-, and Na-doped PbSe from transport, magnetic, and electronic structure studies
Authors: Wiendlocha Bartlomiej , Kim SunPhil , Lee Yeseul , He Bin , Lehr Gloria , Kanatzidis Mercouri G. , Morelli Donald T. , Heremans Joseph P.
Published: March 2017

Eu2+–Eu3+ valence transition is induced by Na doping in Pb1−xEuxSe. This dramatically affects transport, magnetic and electronic properties of the material.
Production of doubly-charged highly reactive species from the long-chain amino acid GABA initiated by Ar9+ionization
Authors: Piekarski Dariusz Grzegorz , Delaunay Rudy , Mika Arkadiusz , Maclot Sylvain , Adoui Lamri , Martín Fernando , Alcamí Manuel , Huber Bernd A. , Rousseau Patrick , Díaz-Tendero Sergio , Domaracka Alicja
Published: March 2017

We present a combined experimental and theoretical study of the fragmentation of multiply-charged γ-aminobutyric acid molecules (GABAz+,z= 2, 3) in the gas phase.
Anion-dependent self-assembly of copper coordination polymers based on pyrazole-3,5-dicarboxylate and 1,2-di(4-pyridyl)ethylene
Authors: Klongdee Fatima , Boonmak Jaursup , Youngme Sujittra
Published: March 2017

Anion-dependent self-assembly of new ternary copper coordination networks containing pyrazole-3,5-dicarboxylate and 1,2-di(4-pyridyl)ethylene with anion exchange studies.
Comment on “Conformational analysis of triphenylphosphine ligands in stereogenic monometallic complexes: tools for predicting the preferred configuration of the triphenylphosphine rotor” by J. F. Costello, S. G. Davies, E. T. F. Gould and J. E. Thomson, Dalton Trans., 2015, 44, 5451
Authors: Brunner Henri , Tsuno Takashi
Published: March 2017

The architecture of triphenylphosphine ligands in compounds [Cp(*)ML1L2PPh3] is determined by CH/π interactions.
Optimized synthesis of π-extended squaraine dyes relevant to organic electronics by direct (hetero)arylation and Sonogashira coupling reactions
Authors: Payne Abby-Jo , Welch Gregory C.
Published: March 2017

This study reports on the synthesis and characterization of four molecular π-extended squaraine compounds relevant to the field of organic electronics.
Semi-continuous multi-step synthesis of lamivudine
Authors: Mandala Devender , Chada Sravanthi , Watts Paul
Published: March 2017

We report the first semi-continuous flow synthesis of lamivudine, an antiretroviral drug used in the treatment of HIV/AIDS.
BODIPY blocked anthroxyl radicals: the substituent effect on reactivity and fluorescence turn-on detection of a hydroxyl radical
Authors: Miao Fang , Lim Zheng Long , Hu Pan , Dong Shaoqiang , Qi Qingbiao , Zhang Xiaojie , Wu Jishan
Published: March 2017

Stable BODIPY-substituted anthroxyl radicals were obtained, which can be used for selective fluorescence turn-on detection of a hydroxyl radical.
“Click” functionalization of dual stimuli-responsive polymer nanocapsules for drug delivery systems
Authors: Yang Wen Jing , Zhao Tingting , Zhou Peng , Chen Simou , Gao Yu , Liang Lijun , Wang Xiaodong , Wang Lianhui
Published: March 2017

“Clickable” and dual stimuli-responsive nanocapsules were developed for facile surface functionalizationviathiol–yne click chemistry and employed as drug nano-carriers.
Alternating and random-sequence polyesters with distinct physical properties
Authors: Peng Chao , Joy Abraham
Published: March 2017

Polyesters with alternating or random-sequence arrangements of indole and ethyl pendant groups exhibit distinct physical properties, such as the nature of fluorescence quenching by fluoride ions.
Bioinspired ultrasound-responsive fluorescent metal–ligand cross-linked polymer assemblies
Authors: Wang Zhenhua , Wang Zhanhua , Xia Hesheng
Published: March 2017

We proposed a general strategy to construct bioinspired ultrasound-responsive fluorescent metal–ligand cross-linked polymer assemblies.
Preparation of polythiophene microrods with ordered chain alignment using nanoporous coordination template
Authors: Kitao Takashi , MacLean Michael W. A. , Le Ouay Benjamin , Sasaki Yotaro , Tsujimoto Masahiko , Kitagawa Susumu , Uemura Takashi
Published: March 2017

The properties of polymeric materials can be amplified by macromolecular alignment.
Exploring structural effects in single-chain “folding” mediated by intramolecular thermal Diels–Alder chemistry
Authors: Hanlon Ashley M. , Martin Ian , Bright Elizabeth R. , Chouinard Jennifer , Rodriguez Kyle J. , Patenotte Gabriel E. , Berda Erik B.
Published: March 2017

We describe a method to fold single polymer chains into nanoparticles using simple thermal Diels–Alder (DA) chemistry.
Ethylene polymerization catalyzed by dinickel complexes with a double-decker structure
Authors: Takeuchi Daisuke , Chiba Yuriko , Takano Shigenaga , Kurihara Hideo , Kobayashi Minoru , Osakada Kohtaro
Published: March 2017

Double-decker dinickel catalysts, even without any substituent on an ortho-position, afforded high molecular weight polyethylene with high crystallinity and less branching.
Synthesis of aliphatic polycarbonates with a tuneable thermal response
Authors: Thomas Anthony W. , Kuroishi Paula K. , Pérez-Madrigal Maria M. , Whittaker Andrew K. , Dove Andrew P.
Published: March 2017

The synthesis of aliphatic polycarbonates with a tuneable thermal-response is reported by a ‘click-and mix’ approach.
Proton transfer and esterification reactions in EMIMOAc-based acidic ionic liquids
Authors: Tran Anh T. , Lam Phuoc H. , Miller Alexandra M. , Walczyk Dustin J. , Tomlin Jay , Vaden Timothy D. , Yu Lei
Published: March 2017

Proton transfer and esterification reactions are observed when formic acid and ionic liquid EMIMOAc are mixed.
The enhanced uranyl–amidoxime binding by the electron-donating substituents
Authors: Qin Zhen , Ren Yiming , Shi Siwei , Yang Chuting , Yu Jie , Wang Shaofei , Jia Jianping , Yu Haizhu , Wang Xiaolin
Published: March 2017

This work describes the enhanced binding between uranyl and amidoxime ligands due to the electron-donating effect of the substituents.
Highly efficient photocatalytic activity of Ag3PO4/Ag/ZnS(en)0.5 photocatalysts through Z-scheme photocatalytic mechanism
Authors: Wei Na , Cui Hongzhi , Wang Mingliang , Wang Xinzhen , Song Xiaojie , Ding Lei , Tian Jian
Published: March 2017

A novel Z-scheme Ag3PO4/Ag/ZnS(en)0.5 composite material was successfully prepared via a facile hydrothermal method and in situ precipitation.
Source separation of V and Fe by two-stage selective leaching during V extraction from stone coal
Authors: Yuan Yizhong , Zhang Yimin , Liu Tao , Chen Tiejun , Huang Jing
Published: March 2017

A novel method of source separation of V and Fe during V extraction from stone coal is developed.
Significantly enhanced electrochemical performance of a ZnCo2O4 anode in a carbonate based electrolyte with fluoroethylene carbonate
Authors: Rong Haibo , Jiang Zhongqing , Cheng Si , Chen Bohong , Zhen Zihao , Deng Binglu , Qin Yanmin , Xie Guiting , Jiang Zhong-Jie , Liu Meilin
Published: March 2017

A facile inexpensive and effective way to improve the performance of a Li/ZnCo2O4 cell by using fluoroethylene carbonate as an additive to the conventional carbonate-based electrolyte has been reported.
Synthesis of phthalate-free plasticizers by hydrogenation in water using RhNi bimetallic catalyst on aluminated SBA-15
Authors: Phan-Vu Duc-Ha , Tan Chung-Sung
Published: March 2017

Phthalate was hydrogenated to phthalate-free product by RhNi nanoparticles on Al-SBA-15.
Correction: Highly recyclable polymer supported ionic liquids as efficient heterogeneous catalysts for batch and flow conversion of CO2 to cyclic carbonates
Authors: Wang Tao , Wang Wenlong , Lyu Yuan , Chen Xingkun , Li Cunyao , Zhang Yan , Song Xiangen , Ding Yunjie
Published: March 2017

Correction for ‘Highly recyclable polymer supported ionic liquids as efficient heterogeneous catalysts for batch and flow conversion of CO2 to cyclic carbonates’ by Tao Wang et al., RSC Adv., 2017, 7, 2836–2841.
Copper-Catalyzed Highly Efficient Esterification of Aldehydes with N-Hydroxyphthalimide via Cross-Dehydrogenative Coupling in Water at Room Temperature
Authors: Jin Can , Su Weike , Guo Zhicheng , Jiang Xinpeng , Zhou Jiadi , Sun Bin
Published: March 2017

A copper-catalyzed cross-dehydrogenative coupling reaction between N-hydroxyphthalimide and aldehydes using PhI(OAc)2 as an oxidant is described. It is reported for the first time to synthesize NHPI esters in water, providing the corresponding NHPI esters in moderate to good yields. This facile and efficient method is eco-friendly and possesses the advantages of mild conditions, short reaction time, and broad substrate scope.
Lipoprotein(a) as a Risk Factor for Venous Thromboembolism: A Systematic Review and Meta-analysis of the Literature
Authors: Gessi Vera , Marcucci Rossella , Gianni Monica , Grandi Anna , Franchini Massimo , Dentali Francesco
Published: March 2017

Elevated plasma levels of lipoprotein(a) (Lp(a)) are associated with increased cardiovascular risk in several clinical studies. However, there is a lack of data supporting a positive association between elevated Lp(a) levels and venous thromboembolism (VTE). Thus, we conducted a systematic review of the literature to better clarify its role as a risk factor for VTE. Medline and the Embase (up to May 2015) electronic databases were used to identify potentially eligible studies. Studies measuring Lp(a) values in adult patients with deep vein thrombosis and/or pulmonary embolism and in a population of patients without a VTE were selected. Studies on patients with major venous thromboembolic events occurring at other unusual site, case reports, and case series were excluded. The odds ratios (ORs) of the association between high values of Lp(a) and VTE and the weighted mean difference (WMD) in Lp(a) levels in cases and in controls were calculated using a random-effect model. Results were presented with 95% confidence interval (CI). Fourteen studies for a total of more than 14,000 patients were finally included in our analysis. Lp(a) was slightly but significantly associated with an increased risk of VTE (OR: 1.56, 95% CI: 1.36, 1.79; 10 studies, 13,541 patients). VTE patients had significantly higher Lp(a) values compared with controls (WMD: 14.46 mg/L, 95% CI: 12.14, 16.78; 4 studies, 470 patients). Lp(a) appeared to be significantly associated with increased risk of VTE. However, Lp(a) levels were only slightly increased in VTE patients compared with controls.
Factor XII Contact Activation
Authors: Naudin Clément , Burillo Elena , Blankenberg Stefan , Butler Lynn , Renné Thomas
Published: March 2017

Contact activation is the surface-induced conversion of factor XII (FXII) zymogen to the serine protease FXIIa. Blood-circulating FXII binds to negatively charged surfaces and this contact to surfaces triggers a conformational change in the zymogen inducing autoactivation. Several surfaces that have the capacity for initiating FXII contact activation have been identified, including misfolded protein aggregates, collagen, nucleic acids, and platelet and microbial polyphosphate. Activated FXII initiates the proinflammatory kallikrein-kinin system and the intrinsic coagulation pathway, leading to formation of bradykinin and thrombin, respectively. FXII contact activation is well characterized in vitro and provides the mechanistic basis for the diagnostic clotting assay, activated partial thromboplastin time. However, only in the past decade has the critical role of FXII contact activation in pathological thrombosis been appreciated. While defective FXII contact activation provides thromboprotection, excess activation underlies the swelling disorder hereditary angioedema type III. This review provides an overview of the molecular basis of FXII contact activation and FXII contact activation–associated disease states.
Point-of-Care Testing in Neurosurgery
Authors: Wessels Lars , Unterberg Andreas , Beynon Christopher
Published: March 2017

Coagulation disorders can have a major impact on the outcome of neurosurgical patients. The central nervous system is located within the closed space of the skull, and therefore, intracranial hemorrhage can lead to intracranial hypertension. Acute brain injury has been associated with alterations of various hemostatic parameters. Point-of-care (POC) techniques such as rotational thromboelastometry are able to identify markers of coagulopathy which are not reflected by standard assessment of hemostasis (e.g., hyperfibrinolysis). In patients with acute brain injury, POC test results have been associated with important outcome parameters such as mortality and need for neurosurgical intervention. POC devices have also been used to rapidly identify and quantify the effects of antithrombotic medication. In cases of life-threatening intracranial hemorrhage, this information can be valuable when deciding over administration of prohemostatic substances or immediate neurosurgical intervention. In elective neurosurgical procedures, POC devices can provide important information when unexpected bleeding occurs or in cases of prolonged operative time with subsequent blood loss. Initial experiences with POC devices in neurosurgical care have shown promising results but further studies are needed to characterize their full potential and limitations.
Early Nephrectomy in Unilateral Multicystic Dysplastic Kidney in Children Cures Hypertension Early: An Observation
Authors: Upadhyaya Vijai , Gupta Manish , Bharti Laxmi , Rao Ram , Kumar Sheo , Kumar Basant
Published: March 2017

Objective Surgery is still indicated as the treatment of choice in subset of patients with unilateral multicystic dysplastic kidney (UMCDK) because of its potential complications and malignant change. The purpose of this study is to present our observation that early nephrectomy may cure hypertension early in children with UMCDK and review the literature.

Materials and Methods We report here four children (two males and two females) with antenatally diagnosed UMCDK with hypertension, treated in the past 4 years. All have antenatal diagnosis of UMCDK and referred to us after their birth. Diagnosis of hypertension (blood pressure > 95th percentile) was made after 3 months of follow-up in all patients. Nephrectomy was performed in all children in variable time duration. Hypertension, urinary tract infection, and desire of parents were the main indication of surgery.

Results All children showed decrease in the size of their dysplastic kidney with time, but hypertension was persistent and needed antihypertensive drugs; even increase in the doses in successive follow-up. After nephrectomy, three children who were operated early got cured having normal blood pressure within variable time duration, while a child, operated late, still had high blood pressure and needed antihypertensive drugs.

Conclusion Early nephrectomy in recently diagnosed hypertension in UMCDK is advisable and can cure hypertension early.

Levels of Evidence The level of evidence is IV (case series with no comparison group).
Nonischemic Priapism in Childhood: A Case Series and Review of Literature
Authors: Schwoebel Marcus , Szavay Philipp , Hacker Hans-Walter
Published: March 2017

Introduction Nonischemic priapism (NIP) in childhood is a very rare affection. In the literature, patients with NIP are described mainly incidental after perineal trauma. Many of them underwent embolization of either internal pudendal artery or bulbocavernosal arteries.

Patients and Methods We report on six boys between 4 and 13 years of age with NIP, treated at our institution between 2008 and 2014. Color Doppler ultrasound (CDU) was performed in all patients as emergency diagnostic evaluation. Patients were treated conservatively, including bed rest, local cooling, and perineal compression. History, etiological factors, clinical findings, diagnostics, and follow-up are presented.

Results Out of the six patients, only one boy had a history of perineal injury with subsequent arteriocavernosal fistula, revealed in CDU. Five patients were circumcised, and one of them suffered from thalassemia minor, but no other underlying disease or etiological factors could be found. In all patients, normal to high blood flow velocities were detected in the cavernosal arteries. Detumescence started with nonoperative treatment within 24 hours in five boys and in one patient with recurrent priapism after 1 week. All six patients remained painless without evidence for an ischemic priapism. None of them suffered from relapse and further erections were observed during follow-up from 3 to 87 months.

Conclusion In contrast to the literature, five out of six boys developed NIP without a previous perineal trauma. The etiology of idiopathic NIP in childhood remains unclear; however, circumcision may play a role as a conditional factor. One etiological thesis could be the release of the neurotransmitter nitric oxide after stimulation of the corpora cavernosa. Conservative treatment proved to be successful in all six patients. During a median follow-up of 55 months (3–87 months), none of the patients showed signs of erectile dysfunction.
Metastatic Prostate Adenocarcinoma to the Brain: Case Reports and Literature Review
Authors: Lam Alexander , Gan Peter
Published: March 2017

Cerebral metastasis secondary to prostatic adenocarcinoma is rare and it is usually a late complication in patients with widespread distant metastases. Here, we report two unusual cases of such a rare condition. Our first case presented with a large frontal contrast-enhancing lesion-associated calcification and a large tumor cyst as shown on computed tomography and magnetic resonance imaging. This is the fifth reported case of prostatic metastasis manifesting as a cystic intraparenchymal tumor in the literature. The second case presented with a large soft tissue mass in the scalp and this lesion appeared to invade through the skull and into the middle cranial fossa. He was not known to have prostate cancer before his initial presentation and it was only diagnosed following histology results of the scalp lesion.
Ökonomische Anreize belegärztlicher im Vergleich zu alternativen Versorgungsformen aus den Perspektiven von Krankenhaus und Vertragsarzt/Belegarzt sowie aus gesundheitssystemischer Sicht
Authors: Hahn Ursula , Mussinghoff Peter
Published: March 2017

Zielsetzung Die ökonomischen Anreize werden als wichtige Einflussgröße für die rückläufige Entwicklung des Belegarztwesens diskutiert. Um diese These zu überprüfen, werden die Erlöse für belegärztliche Versorgung und alternative Versorgungsformen aus Sicht der Akteure Krankenhaus und Vertragsarzt/Belegarzt und aus gesundheitssystemischer Perspektive vergleichend nebeneinander gestellt und die potenziellen Effekte diskutiert.

Methodik Ein neu vorgestelltes Matchingverfahren nutzt den Operations- und Prozedurenschlüssel (OPS) als Intermediär, um Vergleichbarkeit zwischen den Vergütungssystemen Diagnosis-Related Groups (DRG) und Einheitlicher Bewertungsmaßstab (EBM) herzustellen. Die 10 häufigsten matchbaren belegärztlichen DRG werden identifiziert und die Erlöse der Akteure für die alternativen Versorgungsformen bei gleichem OPS gegenübergestellt. Die Krankenhausleistungen werden bei stationärer Versorgung in der Hauptabteilung nach Hauptabteilungs-DRG und in der Belegabteilung nach Belegabteilungs-DRG, ambulante Operationen werden nach Kapitel 31 EBM vergütet. Das Honorar des Vertragsarztes/Belegarztes bemisst sich bei stationärer belegärztlicher Versorgung nach Kapitel 36 EBM und bei ambulanter Versorgung nach Kapitel 31 EBM. Die Gesamtkosten bei belegärztlicher Versorgung entsprechen der Summe aus Belegabteilungs-DRG und dem Honorar nach Kapitel 36 EBM.

Ergebnis Die Erlös-Mediane für die verschiedenen Versorgungsformen und Akteure zeigten folgende Trends: Für das Krankenhaus war die Hauptabteilungs-DRG deutlich attraktiver (im Median € 2320) als Belegabteilungs-DRGs (im Median € 1567). Die Mindereinnahme des Krankenhauses bei ambulanter Versorgung im Vergleich zu der in der Hauptabteilung betrug im Median 81 %. Für den Vertragsarzt/Belegarzt ging eine ambulante Durchführung (im Median € 447) mit einem deutlich höheren Honorar (inkl. Sachkosten) einher als eine belegärztliche (im Median € 270). Unter einem systemischen Kostenblickwinkel ist die ambulante Versorgung am attraktivsten; im Vergleich der alternativen stationären Formen schneidet die belegärztliche Versorgung deutlich günstiger ab als die in einer Hauptabteilung, sie ist rund 23 % günstiger.

Schlussfolgerung Unter Erlösgesichtspunkten sind für beide Akteure Krankenhaus und Vertragsarzt/Belegarzt jeweils andere als die belegärztliche Versorgung attraktiver, die These rückläufiger belegärztlicher Versorgungsrelevanz aufgrund ökonomischer Anreize erweist sich als plausibel. Unter gesundheitsökonomischer Kostenperspektive ist hingegen der belegärztlichen Versorgung im Vergleich zu der in der Hauptabteilung der Vorzug zu geben. Anreize für eine Verlagerung von stationär nach ambulant gehen im Wesentlichen von den für Vertragsärzte/Belegärzte maßgeblichen Vergütungseckdaten aus.
Die Rolle der Laserresektion in der Lungenmetastasenchirurgie
Authors: Macherey S. , Doerr F. , Wahlers T. , Hekmat K.
Published: March 2017

Ziel der Studie Diese Übersichtsarbeit stellt die Laserenukleation im Zuge der Lungenmetastasenchirurgie dar und fasst die aktuelle Evidenz zusammen. Darüber hinaus wird die Laserchirurgie weiteren Resektionsverfahren gegenübergestellt.

Methodik Wir führten eine systematische Literaturrecherche zur Detektion von Fallserien und randomisierten Studien in der Medline und der Cochrane Library durch. Die eingeschlossenen Studien wurden einer qualitativen Analyse unterzogen.

Ergebnisse Die Laser-Metastasektomie ist ein sicheres Verfahren. Im Vergleich von Laserenukleation zu anderen Resektionstechniken ist die Datenlage hinsichtlich klinisch relevanter Endpunkte wie Hospitalisierungszeit, Einlagezeit der Thoraxdrainage und Langzeitüberleben heterogen und kontrovers. Die Laser-Metastasektomie führt sicher zu einer signifikanten Reduktion des Resektionsvolumens. Die Überlebensraten nach Laserresektion sind mit alternativen Resektionsmethoden vergleichbar.

Schlussfolgerung Als parenchymsparende Methode ermöglicht die Laserenukleation selbst bei multiplen Lungenmetastasen oder Patienten mit präoperativ eingeschränkter Lungenkapazität eine onkologisch radikale Resektion.
Indirect exchange interaction between magnetic impurities in a gapped graphene structure
Authors: Rezania H. , Naseri Y. , Shahrestani N.
Published: March 2017

We study exchange interaction between two magnetic impurities in doped gapped graphene (the Ruderman-Kittel-Kasuya-Yosida [RKKY]) interaction by directly computing Green’s function beyond Dirac approximation. Tight binding model Hamiltonian in the presence of magnetic long range ordering has been applied to describe electron dynamics. RKKY interaction as a function of distance between localized moments has been analyzed. It has been shown that a magnetic ordering along the z-axis mediates two different interactions for spin directions which corresponds to a XXZ model interaction between two magnetic moments. The exchange interaction along arbitrary direction between two magnetic moments, has been obtained using the static spin susceptibilities of gapped graphene structure. The effects of spin polarization on the the dependence of exchange interaction on distance between moments are investigated via calculating correlation function of spin density operators. Our results show the chemical potential impacts the spatial behavior of RKKY interaction. Moreover gap parameter effects on RKKY interaction have been investigated in details.
Fluid flows of mixed regimes in porous media
Authors: Celik Emine , Hoang Luan , Ibragimov Akif , Kieu Thinh
Published: March 2017

In porous media, there are three known regimes of fluid flows, namely, pre-Darcy, Darcy, and post-Darcy. Because of their different natures, these are usually treated separately in the literature. To study complex flows when all three regimes may be present in different portions of a same domain, we use a single equation of motion to unify them. Several scenarios and models are then considered for slightly compressible fluids. A nonlinear parabolic equation for the pressure is derived, which is degenerate when the pressure gradient is either small or large. We estimate the pressure and its gradient for all time in terms of initial and boundary data. We also obtain their particular bounds for large time which depend on the asymptotic behavior of the boundary data but not on the initial one. Moreover, the continuous dependence of the solutions on initial and boundary data and the structural stability for the equation are established.
A fast summation method for oscillatory lattice sums
Authors: Denlinger Ryan , Gimbutas Zydrunas , Greengard Leslie , Rokhlin Vladimir
Published: March 2017

We present a fast summation method for lattice sums of the type which arise when solving wave scattering problems with periodic boundary conditions. While there are a variety of effective algorithms in the literature for such calculations, the approach presented here is new and leads to a rigorous analysis of Wood’s anomalies. These arise when illuminating a grating at specific combinations of the angle of incidence and the frequency of the wave, for which the lattice sums diverge. They were discovered by Wood in 1902 as singularities in the spectral response. The primary tools in our approach are the Euler-Maclaurin formula and a steepest descent argument. The resulting algorithm has super-algebraic convergence and requires only milliseconds of CPU time.
Dendrite growth within supercooled liquid tungsten and tungsten-tantalum isomorphous alloys
Authors: Hu L. , Wang W. L. , Yang S. J. , Li L. H. , Geng D. L. , Wang L. , Wei B.
Published: March 2017

The dendrite growth in both supercooled liquid pure W and binary W-Ta isomorphous alloys has been observed and measured by an electrostatic levitation technique. The liquid W and W-x%Ta (x = 25, 50, 75) alloys were substantially supercooled by up to 733 K (0.2 Tm) and 773 K (0.23TL), respectively. The measured density and the ratio of specific heat to emissivity displayed a linearly increasing tendency versus supercooling. The thermal dendrites in supercooled liquid tungsten achieved a maximum growing velocity of 41.3 m·s−1, and the concurrent recalescence process exhibited Johnson-Mehl-Avrami type kinetics. Liquid W-Ta alloys showed stronger supercoolability but a lower maximum dendrite growth velocity of only 35.2 m·s−1. The dendritic growth kinetics was always characterized by a power function relation to liquid supercooling. The microstructure of equiaxed grains transforms to the well-developed dendrites with the increase of supercooling. The grain refinement effect resulting from dendrite fragmentation took place in a moderate supercooling regime in rapidly solidified W-Ta alloys.
The role of guide field in magnetic reconnection driven by island coalescence
Authors: Stanier A. , Daughton W. , Simakov Andrei N. , Chacón L. , Le A. , Karimabadi H. , Ng Jonathan , Bhattacharjee A.
Published: March 2017

A number of studies have considered how the rate of magnetic reconnection scales in large and weakly collisional systems by the modelling of long reconnecting current sheets. However, this set-up neglects both the formation of the current sheet and the coupling between the diffusion region and a larger system that supplies the magnetic flux. Recent studies of magnetic island merging, which naturally include these features, have found that ion kinetic physics is crucial to describe the reconnection rate and global evolution of such systems. In this paper, the effect of a guide field on reconnection during island merging is considered. In contrast to the earlier current sheet studies, we identify a limited range of guide fields for which the reconnection rate, outflow velocity, and pile-up magnetic field increase in magnitude as the guide field increases. The Hall-MHD fluid model is found to reproduce kinetic reconnection rates only for a sufficiently strong guide field, for which ion inertia breaks the frozen-in condition and the outflow becomes Alfvénic in the kinetic system. The merging of large islands occurs on a longer timescale in the zero guide field limit, which may in part be due to a mirror-like instability that occurs upstream of the reconnection region.
The role of agglomeration in the conductivity of carbon nanotube composites near percolation
Authors: Tarlton Taylor , Sullivan Ethan , Brown Joshua , Derosa Pedro A.
Published: March 2017

A detailed study of agglomeration in composite materials containing carbon nanotubes (CNT) is presented. Three dimensional samples with different degrees of agglomeration were created in three different ways, leading to a wider range of geometries available to study. Virtual charges are injected into the computer-generated samples and move through these samples according to a Monte Carlo hopping algorithm. Results show that there is an optimal level of agglomeration that is actually beneficial for charge transport at low volume concentrations, lowering the percolation threshold. It is found that near percolation, a more uniform CNT distribution (less agglomeration) leads to more conductive paths, but with a lower mobility. The optimum level of agglomeration comes from a trade off between these two properties. Beyond this optimum agglomeration state, it is observed that conductivity tends to decrease as dispersion increases at all concentrations studied here. At high concentration (percolated samples), where CNT clumps merge, conductivity seems to be less sensitive to agglomeration.
Rate dependence of grain boundary sliding via time-scaling atomistic simulations
Authors: Hammami Farah , Kulkarni Yashashree
Published: March 2017

Approaching experimentally relevant strain rates has been a long-standing challenge for molecular dynamics method which captures phenomena typically on the scale of nanoseconds or at strain rates of 107 s−1 and higher. Here, we use grain boundary sliding in nanostructures as a paradigmatic problem to investigate rate dependence using atomistic simulations. We employ a combination of time-scaling computational approaches, including the autonomous basin climbing method, the nudged elastic band method, and kinetic Monte Carlo, to access strain rates ranging from 0.5 s−1 to 107 s−1. Combined with a standard linear solid model for viscoelastic behavior, our simulations reveal that grain boundary sliding exhibits noticeable rate dependence only below strain rates on the order of 10 s−1 but is rate independent and consistent with molecular dynamics at higher strain rates.
Heteroepitaxy mechanisms of AlN on nitridated c- and a-plane sapphire substrates
Authors: Funato Mitsuru , Shibaoka Mami , Kawakami Yoichi
Published: March 2017

We investigate the metalorganic vapor phase epitaxy of c-oriented AlN on c- and a-plane sapphire substrates, focusing on the effect of sapphire nitridation on the AlN structure. Prior to AlN growth, the sapphire surface is subjected to nitridation via an in-situ NH3 treatment. We demonstrate that nitridation without H2 thermal etching treatment realizes high quality AlN on both c- and a-plane sapphires, indicating that a reaction between NH3 and oxygen on the sapphire surface is a critical factor in the material growth. It is proposed that nitridation initially creates nanometer-scale inversion domains in the AlN epilayer, but as growth proceeds, the N-polar domains are annihilated, leaving voids. Such growth behaviors can be regarded as spontaneous selective area growth with strain-adsorbing void formation, and lead to crack-free, ∼5 μm thick AlN layers, which produce x-ray line widths as narrow as 180 and 483 arc sec for the (0002) and (101¯2) reflections, respectively, on c-plane sapphire, and 237 and 433 arc sec for these reflections on a-plane sapphire.
Dependence of the 0.5 × (2e2/h) conductance plateau on the aspect ratio of InAs quantum point contacts with in-plane side gates
Authors: Das P. P. , Jones A. , Cahay M. , Kalita S. , Mal S. S. , Sterin N. S. , Yadunath T. R. , Advaitha M. , Herbert S. T.
Published: March 2017

The observation of a 0.5 × (2e2/h) conductance plateau in asymmetrically biased quantum point contacts (QPCs) with in-plane side gates (SGs) has been attributed to the onset of spin-polarized current through these structures. For InAs QPCs with the same width but a longer channel length, there is roughly a fourfold increase in the range of common sweep voltage applied to the SGs over which the 0.5 × (2e2/h) plateau is observed when the QPC aspect ratio (ratio of length over the width of the narrow portion of the structure) is increased by a factor 3. Non-equilibrium Green's function simulations indicate that the increase in the size of the 0.5 × (2e2/h) plateau is due to an increased importance, over a larger range of common sweep voltage, of the effects of electron-electron interactions in QPC devices with a larger aspect ratio. The use of asymmetrically biased QPCs with in-plane SGs and large aspect ratio could therefore pave the way to build robust spin injectors and detectors for the successful implementation of spin field effect transistors.