bluuebunny/crossref_metadata_2025 huggingface dataset:
Phytochemical Profile and Biological Activities of Helianthemum canum l. baumg. from Turkey
Authors: Baldemir Ayşe , Gökşen Neslihan , Ildız Nilay , Karatoprak Gökçe Şeker , Koşar Müberra
Published: March 2017

In the current study, antioxidant, antibacterial activities, and the phenolic compositions of extracts from Helianthemum canum L. Baumg. (Apiaceae) aerial parts were investigated for the first time. The H. canum was extracted with 70% methanol (HCMeOH) and water (HCW). Both extracts were determined by total phenolic contents (3 mg/ml), flavonoids (1.5 mg/ml), flavonols (1.5 mg/ml), qualitative–quantitative compositions, iron (II) chelation activities (0.1 – 5 mg/ml), free radical scavenging activities (DPPH•: 0.01 – 0.6 mg/ml and ABTS+•: 0.125 – 0.5 mg/ml) and the effect upon inhibition of β‐carotene/linoleic acid co‐oxidation (1 mg/ml). The peroxidation level was also determined using the thiobarbituric acid method (0.01 – 1.5 mg/ml). The results of the activity tests given as IC50 values were estimated from non‐linear algorithm and compared with standards. Antibacterial activities of extracts and standards were evaluated against Gram‐negative and ‐positive ten standard strains using disc diffusion and broth microdilution methods. The MIC results (312.5 – 2500 μg/ml) against tested microorganisms varied from 625 to 2500 μg/ml. In HPLC analysis, 3,5‐dihydroxybenzoic acid was found as the main substance in both extracts. These results showed that HCMeOH was richer in phenolic compounds (284.13 ± 0.30 mg GAE/g extract) from HCW (244.55 ± 0.35 mg GAE/g extract). In conclusion, H. canum extracts showed in vitro antibacterial and antioxidant activities.
Chemical Composition and Antibacterial Activity of Iranian Lavandula × hybrida
Authors: Bajalan Iman , Rouzbahani Razieh , Pirbalouti Abdollah Ghasemi , Maggi Filippo
Published: March 2017

Lavandin (Lavandula × hybrida) is an evergreen shrub and cultivated worldwide for its essential oil which possesses various biological activities. In this study, the essential oils were isolated from the leaves of ten lavandin populations in western Iran. The hydrodistilled essential oils were analyzed by GC‐FID/MS. Results indicated significant differences (P ≤ 0.05) among the various populations for the main essential oil constituents. The major components from different populations were 1,8‐cineole (31.64 – 47.94%), borneol (17.11 – 26.14%), and camphor (8.41 – 12.68%). In vitro antibacterial activity was evaluated against S. agalactiae, S. aureus, E. coli, and K. pneumoniae. The inhibition zones were in the range of 09.36 mm for S. aureus to 23.30 mm for E. coli. Results indicated that there was a significant correlation between essential oil composition and level of antibacterial efficacy expressed as inhibition zones.
The comparative safety and effectiveness of bivalirudin versus heparin monotherapy in patients on dialysis undergoing percutaneous coronary intervention: Insights from the Blue Cross Blue Shield of Michigan cardiovascular consortium
Authors: Sukul Devraj , Seth Milan , Schreiber Theodore , Khandelwal Akshay , Cannon Louis A. , LaLonde Thomas A. , Gurm Hitinder S.
Published: March 2017

Background

Dialysis patients are at a higher risk of bleeding after percutaneous coronary intervention (PCI); however, due to their exclusion from randomized clinical trials, the optimal antithrombotic regimen for this population remains unknown. We sought to evaluate the comparative safety and effectiveness of bivalirudin monotherapy versus unfractionated heparin (UFH) monotherapy in dialysis patients undergoing PCI.

Methods

We included dialysis patients who underwent PCI in a multicenter registry between January 2010 and September 2015 at 47 Michigan hospitals. We compared in‐hospital outcomes between bivalirudin versus UFH; excluding those treated with glycoprotein IIb/IIIa inhibitors. Optimal full matching was used to account for the nonrandom use of these drugs.

Results

Of 177,963 patients who underwent PCI, 4,303 (2.4%) were on dialysis. Among those, 1,257 (29.2%) received bivalirudin monotherapy and 2,112 (49.1%) received UFH monotherapy. Patients treated with bivalirudin had fewer comorbidities. After matching, there were no significant differences in outcomes between those who received bivalirudin versus UFH: bleeding (adjusted odds ratio: 0.67; 95% confidence interval: 0.41–1.07; P = 0.093); major bleeding (0.81; 0.19–3.50; P = 0.77); transfusion (1.01; 0.77–1.33; P = 0.96); repeat PCI (0.57; 0.14–2.24; P = 0.42); stent thrombosis (0.56; 0.05–5.83; P = 0.63); and death (0.84; 0.46–1.51; P = 0.55).

Conclusions

We found no significant differences in in‐hospital outcomes between bivalirudin and UFH monotherapy among dialysis patients undergoing PCI. Randomized clinical trials are needed to determine the optimal anticoagulant regimen for this population. © 2017 Wiley Periodicals, Inc.
Factors associated with deferred lesion failure following fractional flow reserve assessment in patients with diabetes mellitus
Authors: Kennedy Mark W. , Fabris Enrico , Hermanides Renicus S. , Kaplan Emel , Borren Nanette , Berta Balazs , Koopmans Petra C. , Ottervanger Jan Paul , Suryapranata Harry , Kedhi Elvin
Published: March 2017

Objective

To explore the predictors of deferred lesion failure (DLF) in patients with diabetes mellitus (DM) and lesions with a fractional flow reserve (FFR) >0.80 and to examine whether a predictive relationship between negative FFR values (>0.80–1.00) and DLF exists.

Background

DM is associated with rapidly progressive atherosclerosis and predictors of DLF in FFR negative lesions in this high‐risk group are unknown.

Methods

All DM patients who underwent FFR‐assessment between 1/01/2010 and 31/12/2013 were included, and followed until 1/7/2015. Patients carrying ≥1 FFR negative lesion(s) were assessed for DLF, and multivariate models used to identify independent factors associated with DLF.

Results

A total of 205 patients with 252 FFR >0.80 lesions were identified. At a mean follow‐up of 3.1 ± 1.4 years, DLF occurred in 29/205 (14.1%) patients, 31/252 (12.3%) lesions. Using marginal Cox regression multivariate analysis, insulin requiring DM [HR 2.24 (95%CI; 1.01–4.95), P = 0.046] and prior revascularization [HR 2.70 (95%CI 1.21–6.01), P = 0.015] were identified as being associated with a higher incidence of DLF. Absolute FFR values in FFR negative lesions in DM patients are not predictive of DLF (receiver operating characteristics curve analysis: area under the curve: 0.57 ± 0.06, 95%CI 0.46–0.69).

Conclusions

In DM patients with FFR negative lesions, insulin requiring DM and prior revascularization are predictors for DLF. In contrast to non‐DM patients, no predictive relationship between absolute negative FFR values (ranging >0.80–1.00) and the risk of DLF exists in DM patients. © 2017 Wiley Periodicals, Inc.
Afterload mismatch after transcatheter mitral valve repair with MitraClip for degenerative mitral regurgitation in acute cardiogenic shock
Authors: Tang Gilbert H.L. , Cohen Martin , Dutta Tanya , Undemir Cenap
Published: March 2017

Acute afterload mismatch after surgery for mitral regurgitation (MR) with transient left ventricular dysfunction is well known, but not described after transcatheter mitral valve repair with MitraClip, except in functional MR and cardiomyopathy. MitraClip to manage acute severe MR and cardiogenic shock has also been rarely reported. We report here a 77‐year‐old female who presented with acute severe degenerative MR from a flail posterior leaflet, with cardiogenic shock requiring intra‐aortic balloon pump support. She was medically stabilized and underwent successful MitraClip repair with mild residual MR, but developed acute afterload mismatch and severe left ventricular dysfunction and shock 24 hr after her procedure. Patient was medically managed with intra‐aortic balloon pump and inotropic support. She subsequently fully recovered with normal ventricular function and was discharged after 14 days. Patient remained asymptomatic in NYHA I functional class 9 months after MitraClip repair, with mild residual MR and normal ventricular function. MitraClip repair in patients with acute severe degenerative MR and cardiogenic shock is a less invasive and potentially safer alternative to open surgery, but acute afterload mismatch may occur and requires prompt diagnosis and management for a successful outcome. © 2017 Wiley Periodicals, Inc.
Covered stent implantation through a single 8‐french guide catheter for the management of a distal coronary perforation
Authors: Sandoval Yader , Lobo Angie S. , Brilakis Emmanouil S.
Published: March 2017

Distal coronary perforation can cause early or late tamponade and is usually treated with fat or coil embolization. An alternative treatment strategy is occlusion of the ostium of the perforated vessel via implantation of a covered stent in the main vessel, which is typically achieved using the ping‐pong guide catheter technique. In this technique, a balloon is inflated over one guide catheter to stop pericardial bleeding and a covered stent is delivered through a second guide catheter due to inability to fit both a balloon and a covered stent through a single guide catheter. With development of lower profile rapid exchange covered stents, a single guide catheter can be used to both occlude the target vessel and deliver the covered stent. We describe a case of distal vessel perforation in which a balloon was inflated to stop pericardial bleeding, followed by delivery of a covered stent (Graftmaster, Abbott Vascular) through a single 8‐Fr guide catheter. This “block and deliver” technique represents a novel paradigm for treating coronary perforations through a single guide catheter, obviating the need for the ping‐pong guide catheter technique. © 2017 Wiley Periodicals, Inc.
Anchor balloon, buddy wire, and wire and sheath techniques to deploy percutaneous pulmonary valves in tetralogy of fallot patients
Authors: Shah Ruchit R. , Poommipanit Paul , Law Mark A. , Amin Zahid
Published: March 2017

Advances in surgical techniques in tetralogy of Fallot (TOF) patients have improved survival of these patients into adulthood. The procedure requires right ventricular outflow tract or trans‐annular patch with resultant pulmonary stenosis and/or regurgitation. As such, adult patients seen with this condition may have increasing right ventricular hypertrophy and/or right ventricular dilation. Recently, the Sapien XT valve (Edwards Lifesciences, CA) was approved by the FDA for pulmonary implantation. In some cases, advancing the valve in right ventricular outflow tract is difficult. This is a case series of delivering Sapien XT valves in TOF patients with severe pulmonary regurgitation and/or stenosis, using the anchor balloon, buddy wire, and the novel, wire and sheath techniques. © 2017 Wiley Periodicals, Inc.
Exercise‐induced saphenous vein graft spasm prevented by stenting
Authors: Boliek William G. , Kereiakes Dean J. , Chugh Atul
Published: March 2017

Recurrence of anginal symptoms following coronary artery bypass surgery is usually secondary to graft closure or progression of native vessel disease. The present case demonstrates severe exercise‐induced saphenous vein graft (SVG) spasm associated with transmural ischemia refractory to maximal vasodilator therapy. Symptoms resolved and exercise electrocardiography normalized following stenting of SVG regions demonstrating spasm. © 2017 Wiley Periodicals, Inc.
Exuberant liver adenomatosis presenting with iron deficiency anemia
Authors: Mota Catarina , Carvalho Ana Margarida , Fonseca Válter , Silva Marisa Teixeira , Victorino Rui M. M.
Published: March 2017

Key Clinical Message

Intratumoral or intraperitoneal hemorrhage is a recognized complication of liver adenomatosis. We report a case of multifocal massive liver adenomatosis presenting as chronic iron deficiency anemia. Clinicians’ awareness about this atypical presentation not highlighted in the literature is important to allow timely diagnosis and surgical intervention to prevent fatal complications.
A case of HER2‐positive male occult breast carcinoma with skin and lymph node metastases that exhibited complete response to trastuzumab monotherapy
Authors: Kuninaka Kouichi , Takahashi Ryo , Nakagawa Yutaka , Nishimaki Tadashi
Published: March 2017

Key Clinical Message

Metastatic male occult HER2‐positive breast cancer can be successfully treated with trastuzumab monotherapy.
Providing full recovery with single‐dose intravenous reteplase in a patient presented to emergency department with acute ischemic stroke
Authors: Özlüer Yunus Emre , Avcil Mücahit
Published: March 2017

Key Clinical Message

Administration of intravenous reteplase might be a choice of treatment of acute ischemic stroke.
Allergic contact dermatitis following drug rash due to chlorpheniramine maleate
Authors: Shikino Kiyoshi , Masuyama Takako , Yamashita Tomoko , Ikusaka Masatomi
Published: March 2017

Key Clinical Message

Allergic contact dermatitis (ACD) is one of the common causes of facial swelling. Clinical clues for diagnosing ACD include a rash that spares the area behind the ears, nasolabial folds, and under the chin. Once clinicians suspect ACD, the substances that cause contact dermatitis should be avoided.
First reported case of Simpson–Golabi–Behmel syndrome in a female fetus diagnosed prenatally with chromosomal microarray
Authors: Støve Heidi Kristine , Becher Naja , Gjørup Vibike , Ramsing Mette , Vogel Ida , Vestergaard Else Marie
Published: March 2017

Key Clinical Message

Simpson–Golabi–Behmel syndrome (SGBS) is a rare X‐linked syndrome. Female carriers may have mild manifestations. Macrosomia, polyhydramnios, and kidney and urinary tract anomalies are common findings in male fetuses. We present the first case of a severely affected female fetus with stigmata of SGBS and a deletion involving the GPC3 gene.
Recent Advances in Biosensing for Neurotransmitters and Disease Biomarkers using Microelectrodes
Authors: Chandra Shaneel , Siraj Shajahan , Wong Danny K. Y.
Published: March 2017

This Minireview focuses on recent advances in the applications of microelectrodes to detect and monitor targeted analytes in bioelectrochemical processes. Notably, these processes are electrochemically driven reactions that involve the detection of targets from the biological realm. Wide‐ranging applications of electrochemical sensors have been reported in the last few decades in various research fields, owing to favorable attributes such as high selectivity and sensitivity, rapid analysis, simplicity, easy fabrication, and cost effectiveness. Accordingly, in this Minireview, we explore recent advances in bioelectrochemistry based on small detection probes or structures modified for a variety of analytes, exploiting multi‐approach advantages of enhanced electrochemical detection surface or targeted analyte pursuit. The target analytes included in this Minireview are neurotransmitters and disease biomarkers detected using enzymatic and non‐enzymatic electrode modifications.
Experimental Study on the Influence of Filling Method and Particle Material on the Packed‐Bed Porosity
Authors: Pottbäcker Jennie , Hinrichsen Olaf
Published: March 2017

The reliable prediction of the pressure drop of packed beds requires an accurate estimation of the packed‐bed porosity as its error propagation multiplies the occurring errors by a factor of about four. The commonly used correlations to determine porosity depend only on the tube to particle diameter ratio. To improve accuracy, the influence of the filling method and of material properties, in particular surface roughness, density, and restitution coefficient are investigated for random packings of spheres in cylindrical confining walls. Furthermore, statistical methods are applied to identify interconnecting effects between these influencing parameters.
Die lebende anionische Polymerisation
Authors: Leibig Daniel , Morsbach Jan , Grune Eduard , Herzberger Jana , Müller Axel H.E. , Frey Holger
Published: March 2017

Vor sechzig Jahren entdeckte Michael Szwarc die lebende anionische Polymerisation. Trotz ihrer hohen synthetischen Anforderungen ist sie bis heute die präziseste Methode zur Herstellung von wohldefinierten Polymeren und inspirierte zahlreiche neue Polymerisationsmethoden. Maßgeschneiderte Blockcopolymere finden sich in den verschiedensten Anwendungen von High‐End‐Verpackungsmaterialien über die Elektronik bis hin zu Nanomedizin.
On the evaluation of Alkaline‐Surfactant‐Polymer flooding in a field scale: Screening, modelling, and optimization
Authors: Azamifard Arash , Bashiri Gholamreza , Gerami Shahab , Hemmati‐Sarapardeh Abdolhossein
Published: March 2017

Chemical enhanced oil recovery methods, including alkaline surfactant polymer (ASP) flooding, have found special significance for oil reservoirs. ASP flooding provides different situations based on ratio of injection of three ASP components. This study identifies the behaviour of injection components and their interaction, investigating the synergy between them. To this end, an Iranian oil reservoir is studied. The factors influencing the injection process are identified and then a combination of these factors and the concentration of ASP components are modelled. All modelling results are fitted with R‐squared and adjusted R‐squared values above 0.96. Finally, the optimization is conducted to determine the best injection scenario. The most important aspect of this study is to investigate simultaneously the effect of different parameters of ASP in a real case. The screening results show that the effect of polymer on viscosity is the most influential factor in ASP flooding. The modelling results show that water cut in the case of simultaneous injection of three components is less than other cases of injection. This represents the synergy of components in the injection process during ASP flooding. The miscibility between water and polymer solution also leads to less produced water and more produced oil. In the final stage, the optimization results show that the optimal scenario is injection of surfactant and polymer with the greatest amount of miscibility between water and polymer solution. It can be concluded that with this approach, ASP injection can efficiently be analyzed and optimized from a technical point of view.
Corrigendum: Viscosity Solutions to Complex Monge‐Ampère Equations
Authors: Eyssidieux Philippe , Guedj Vincent , Zeriahi Ahmed
Published: March 2017

The proof of the comparison principle in the article cited above is not complete. We provide here an alternative proof, valid in the ample locus of any big cohomology class, and discuss the resulting modifications.© 2017 Wiley Periodicals, Inc.
Enzymatic Electrosynthesis of Formic Acid through Carbon Dioxide Reduction in a Bioelectrochemical System: Effect of Immobilization and Carbonic Anhydrase Addition
Authors: Srikanth Sandipam , Alvarez‐Gallego Yolanda , Vanbroekhoven Karolien , Pant Deepak
Published: March 2017

The enzymatic electrosynthesis of formic acid from the reduction of carbon dioxide (CO2) by using formate dehydrogenase (FDH) as a catalyst at the cathode in both its free and immobilized forms was studied in detail in a bioelectrochemical system (BES). The essential role of solubilizing CO2 for its conversion was also studied by adding carbonic anhydrase (CA) to the FDH enzyme in both its free and immobilized forms. FDH alone in the free form showed large variation in the reduction current [(−6.2±3.9) A m−2], whereas the immobilized form showed less variation [(−3.8±0.5) A m−2] due to increased enzyme stability. The addition of CA with FDH increased the consumption of the current in both forms due to the fact that it allowed rapid dissolution of CO2, which made it available for the catalytic reaction with FDH. Remarkably, stable consumption of the current was observed throughout the operation if both CA and FDH were immobilized onto the electrode [(−3.9±0.2) A m−2]. Product formation by the immobilized enzyme was also continued for three repetitive cycles, which revealed the longevity of the enzyme after immobilization. The recyclability of NADH (NAD=nicotinamide adenine dinucleotide) was also clearly evidenced on the derivative voltammetric signature. Extension of this study for continuous and long‐term operation may reveal more possibilities for the rapid capture and conversion of CO2.
The Quantitative Characterization of Functional Allosteric Effects
Authors: Kenakin Terry
Published: March 2017

Seven‐transmembrane receptors (7TMRs or GPCRs [G protein–coupled receptors]) are nature's prototypic allosteric proteins in that they mediate the interaction between ligand binding to the receptor and the receptor interacting with another cell signaling protein. A growing class of potential drugs acting through 7TMRs are allosteric in nature in that they bind to a separate site on the receptor protein to modify the interactions between the receptor, natural binding/orthosteric ligand, and signaling proteins. Two main allosteric compound categories are those that increase (positive allosteric modulators [PAMs]) and those that decrease (negative allosteric modulators [NAMs]) receptor‐mediated responses. Described in this overview are the molecular parameters used to measure and quantify the interaction of PAMs and NAMs with GPCRs. © 2017 by John Wiley & Sons, Inc.
Design Principles for Covalent Organic Frameworks in Energy Storage Applications
Authors: Alahakoon Sampath B. , Thompson Christina M. , Occhialini Gino , Smaldone Ronald A.
Published: March 2017

Covalent organic frameworks (COFs) are an exciting class of porous materials that have been explored as energy‐storage materials for more than a decade. This review discusses efforts to develop these materials for applications in gas and electrical power storage. Some of the design strategies for developing the gas sorption properties of COFs and mechanistic studies on their formation are also discussed.
Quantum circuit physical design flow for 2D nearest‐neighbor architectures
Authors: Farghadan Azim , Mohammadzadeh Naser
Published: March 2017

The physical design process takes a netlist generated by the logic synthesis process and places and routes the netlist on a physical platform. In some physical platforms, physical qubits must be placed on a 2D grid. Each node of the grid represents a qubit. In these platforms, performing quantum gates on non‐adjacent qubits is very error prone or hard to control. Therefore, quantum gates are limited to be performed on adjacent qubits. A communication channel of swap gates needs to be constructed if the qubits in the logical circuit are not adjacent. The algorithms used for mapping of qubits on the grid have important roles in reducing the number of swap gates and thus decreasing of the circuit latency. Focusing on this issue, in this paper, a flow for physical design of quantum circuits on a 2D grid is proposed. It contains three algorithms for finding the order of qubit placement, physical qubit placement, and routing. Simulation results show that the proposed flow not only decreases the average number of swap gates by about 16% compared with the best in the literature but also improves the average runtime by about 94% compared with it. Copyright © 2017 John Wiley & Sons, Ltd.
Selectivity and sensitivity enhancement methods for high‐data‐rate super‐regenerative receiver
Authors: Mousavi Samaneh , Saeedi Saeed
Published: March 2017

This paper describes selectivity and sensitivity performance evaluations and improvement methods for an on–off keying super‐regenerative (SR) receiver. A slope‐controlled quasi‐exponential quench waveform, generated by a low‐complexity PVT‐tolerant quench generator circuit, is proposed to increase data rate and reduce the receiver 3‐dB bandwidth, thereby preventing oscillation caused by out‐of‐band injected signals and improving the receiver selectivity. The SR receiver sensitivity is also enhanced by a noise‐canceling front‐end topology with single‐ended to differential (S2D) signal converter. To exemplify these techniques, we designed an SR receiver with the proposed front‐end and quench waveform generator in a 0.18‐μm CMOS technology. Theoretical analyses and circuit simulations show 30% and 65% reduction in 3‐dB bandwidth of the SR receiver at 25 Mbps data rate by employing the proposed quench signal compared with piecewise‐linear and trapezoidal quench waveforms, respectively. Performance of the proposed front‐end is evaluated by a fast bit‐error‐rate estimation procedure, based on circuit noise simulations and statistical analyses, without the need for time‐consuming transient‐noise simulations. Accuracy of the procedure has been verified by comparing its results with transient‐noise simulations. According to the estimated bit‐error‐rate curves, the noise‐canceling topology with S2D converter enhances the SR receiver sensitivity by 9 dB. Copyright © 2017 John Wiley & Sons, Ltd.
Performance analysis of adaptive limited feedback coordinated zero‐forcing multicell systems in time‐varying channels: A practical approach
Authors: Balaji S. , Mallick P.S.
Published: March 2017

In this paper, coordinated limited feedback zero‐forcing beamforming multicell system in time‐varying channel is studied. In time‐varying channels, the actual rate loss arising from error in channel quantization of both interuser and intercell inferences is quantified in this work. Using the actual degradation of rate loss, a limited feedback bit allocation is proposed to reduce interuser and intercell interference simultaneously with feedback update period as one of the parameters. Furthermore, the scaling law of bits required to maintain a constant rate loss is formulated in varying channel conditions for a given feedback update period. Simulation results demonstrated the practical feedback requirement in multicell systems in the presence of both intercell and interuser interference over conventional schemes to maintain a constant rate offset. The key finding from the proposed feedback allocation is that practically much higher allocation of feedback bits and feedback scaling are required in time‐varying channels to reduce throughput degradation.
Increase communication between individuals with disabilities and law enforcement
Authors: Sutton Halley
Published: March 2017

Nearly one‐third to one‐half of all people killed in police shootings have developmental, intellectual, or physical disabilities, according to the best estimates included in a white paper published by the Ruderman Foundation entitled “Media Coverage of Law Enforcement Use of Force and Disability.” In a webinar commissioned and directed by the National Center on Criminal Justice and Disability, a panel of grassroots activists and experts discussed how diversity and disability factor into the use of force by police officers. They also discussed strategies for increasing communication between disabled students and police officers, understanding how the intersectionality of diversity and disability compounds already fraught situations, and keeping your students safe both on and off campus.
Students with disabilities as likely to enter STEM fields as those without disabilities
Authors: Sutton Halley
Published: March 2017

Students with disabilities are as likely as typically developing students to enter science and engineering fields during college, according to data from the National Science Foundation.
Ultrastructural alterations of pancreatic beta cells in human diabetes mellitus
Authors: Masini Matilde , Martino Luisa , Marselli Lorella , Bugliani Marco , Boggi Ugo , Filipponi Franco , Marchetti Piero , De Tata Vincenzo
Published: March 2017

Background

Both types of diabetes are characterized by beta‐cell failure and death, leading to insulin insufficiency. Very limited information is currently available about the ultrastructural alterations of beta cells in human diabetes. Our aim was to provide a comprehensive ultrastructural analysis of human pancreatic islets in type 1 (T1D) and type 2 (T2D) diabetic patients.

Methods

We performed a morphometric electron microscopy evaluation of beta cells obtained from the pancreas of 8 nondiabetic (ND), 5 T1D, and 8 T2D organ donors.

Results

A lower amount of beta cells was found in both T1D and T2D than in ND islets, whereas alpha cells were increased only in T2D. An increased number of bi‐hormonal cells (showing both insulin and glucagon granules in their cytoplasm) were found in T1D. Insulin granules were less represented in T2D than in ND beta cells, whereas no significant changes were found in T1D. Volume density of the endoplasmic reticulum was increased in T2D and unchanged in T1D; mitochondria number and volume were significantly higher in T2D than in ND beta cells, whereas no significant differences were found in T1D. In both T1D and T2D, more beta cells showed signs of apoptosis than in ND.

Conclusions

Our results show that in each type of diabetes, beta cells exhibit specific ultrastructural alterations, whose better understanding might improve therapeutic strategies.
Plasma Sfrp5 levels correlate with determinants of the metabolic syndrome in Chinese adults
Authors: Xu Qiuyan , Wang Hongyan , Li Yang , Wang Jinzhi , Lai Yerui , Gao Lin , Lei Lu , Yang Gangyi , Liao Xin , Fang Xia , Liu Hua , Li Ling
Published: March 2017

Background

Secreted frizzled‐related protein‐5 (Sfrp5) is a novel adipokine, and it has been found to link insulin resistance with diabetes. Animal studies have revealed the role of Sfrp5 in regulating lipid and glucose metabolism. The objective of this study was to investigate the relationship between Sfrp5 and the metabolic syndrome (MetS) in a cross‐sectional study.

Methods

We conducted a series of cross‐sectional studies of Chinese population including 194 control participants and 90 MetS patients. Circulating Sfrp5 concentrations were determined by ELISA. The relationships between circulating Sfrp5 levels and MetS components were assessed.

Results

Circulating Sfrp5 was significantly lower in newly examined MetS patients than in control participants (49.1 ± 17.2 vs 61.6 ± 23.2 μg/L, P < .01). Circulating Sfrp5 correlated negatively with markers of adiposity (waist‐to‐hip ratio, body mass index, and free fatty acids, P < .001 or P < .05). Furthermore, Sfrp5 levels correlated with fasting insulin, 2 h‐ins, fasting blood glucose, 2 h post‐glucose load blood glucose, HbA1c, and homeostasis model assessment of insulin resistance. In addition, circulating Sfrp5 levels were closely associated with blood pressure, high‐density lipoprotein cholesterol, triglycerides, and atherosclerotic index. Circulating concentrations of Sfrp5 decreased progressively with continued increases in the numbers of MetS components. The analysis of receiver operating characteristic curves revealed that the best cutoff value for circulating Sfrp5 to predict MetS was 46.8 μg/L (sensitivity 70.1 %, specificity 47.8 %, and AUC 0.66).

Conclusions

We conclude that Sfrp5 may be an adipokine that is associated with the pathogenesis of MetS in humans.
Helophyte impacts on the response of hyporheic invertebrate communities to inundation events in intermittent streams
Authors: Baranov Viktor , Milošević Djuradj , Kurz Marie J. , Zarnetske Jay P. , Sabater Francesc , Marti Eugenia , Robertson Anne , Brandt Tanja , Sorolla Albert , Lewandowski Jörg , Krause Stefan
Published: March 2017

The effects of experimental inundation on invertebrate communities in artificial flumes fed with treated wastewater were investigated. Flumes, designed to simulate intermittent river conditions, were planted with 3 species of helophytes widely used in river restoration around the water‐stressed regions of Europe. Different species of vegetation had different capabilities to reduce the invertebrate's negative reaction to inundation, related mostly to rhizosphere density. Of the 3 helophyte species tested, only 1, Lysimachia vulgaris, showed significant capabilities to reduce invertebrate negative reaction on inundation. Species richness of invertebrates before and after the inundation did not change in any of the flumes, whereas species density significantly declined in all flumes except one planted with L. vulgaris. This helophyte species was associated with high densities of the Culicidae larvae (common mosquitos), which has severe implications for river restoration and vector management in the region. This study indicates that the selection and establishment of different helophyte species will impact invertebrate communities in restored streams, especially streams experiencing variable inundation conditions.
Groundcover community assembly in high‐diversity pine savannas: seed arrival and fire‐generated environmental filtering
Authors: Harms Kyle E. , Gagnon Paul R. , Passmore Heather A. , Myers Jonathan A. , Platt William J.
Published: March 2017

Environmental filtering—abiotic and biotic constraints on the demographic performance of individual organisms—is a widespread mechanism of selection in communities. A given individual is “filtered out” (i.e., selectively removed) when environmental conditions or disturbances like fires preclude its survival and reproduction. Although interactions between these filters and dispersal from the regional species pool are thought to determine much about species composition locally, there have been relatively few studies of dispersal × filtering interactions in species‐rich communities and fewer still where fire is also a primary selective agent. We experimentally manipulated dispersal and filtering by fire (pre‐fire fuel loads and post‐fire ash) in species‐rich groundcover communities of the longleaf pine ecosystem. We tested four predictions: (1) That species richness would increase with biologically realistic dispersal (seed addition); (2) that the immediate effect of increased fuels in burned communities would be to decrease species richness, whereas the longer‐term effects of increased fuels would be to open recruitment opportunities in the groundcover, increase species richness, and increase individual performance (growth) of immigrating species; (3) that adding ash would increase species richness; and (4) that increased dispersal would generate larger increases in species richness in plots with increased fuels compared to plots with decreased fuels. We found that dispersal interacted with complex fire‐generated filtering during and after fires. Dispersal increased species richness more in burned communities with increased and decreased fuels compared to burned controls. Moreover, individuals of immigrating species generally grew to larger sizes in burned communities with increased fuels compared to burned controls. In contrast to dispersal and fuels, ash had no effect on species richness directly or in combination with other treatments. We conclude that filtering occurs both during fires and in the post‐fire environment and that these influences interact with dispersal such that the consequences are only fully revealed when all are considered in combination. Our experiment highlights the importance of considering the dynamic interplay of dispersal and selection in the assembly of species‐rich communities.
Effects of experimentally reduced snowpack and passive warming on montane meadow plant phenology and floral resources
Authors: Sherwood J. A. , Debinski D. M. , Caragea P. C. , Germino M. J.
Published: March 2017

Climate change can have a broad range of effects on ecosystems and organisms, and early responses may include shifts in vegetation phenology and productivity that may not coincide with the energetics and forage timing of higher trophic levels. We evaluated phenology, annual height growth, and foliar frost responses of forbs to a factorial experiment of snow removal (SR) and warming in a high‐elevation meadow over two years in the Rocky Mountains, United States. Species included arrowleaf balsamroot (Balsamorhiza sagittata, early‐season emergence and flowering) and buckwheat (Eriogonum umbellatum, semi‐woody and late‐season flowering), key forbs for pollinator and nectar‐using animal communities that are widely distributed and locally abundant in western North America. Snow removal exerted stronger effects than did warming, and advanced phenology differently for each species. Specifically, SR advanced green‐up by a few days for B. sagittata to >2 wk in E. umbellatum, and led to 5‐ to 11‐d advances in flowering of B. sagittata in one year and advances in bud break in 3 of 4 species/yr combinations. Snow removal increased height of E. umbellatum appreciably (~5 cm added to ~22.8 cm in control), but led to substantial increases in frost damage to flowers of B. sagittata. Whereas warming had no effects on E. umbellatum, it increased heights of B. sagittata by >6 cm (compared to 30.7 cm in control plots) and moreover led to appreciable reductions in frost damage to flowers. These data suggest that timing of snowmelt, which is highly variable from year to year but is advancing in recent decades, has a greater impact on these critical phenological, growth, and floral survival traits and floral/nectar resources than warming per se, although warming mitigated early effects of SR on frost kill of flowers. Given the short growing season of these species, the shifts could cause uncoupling in nectar availability and timing of foraging.
Evaluation of various approaches to the isolation of steroid hormones from urine samples prior to FASS‐MEKC analysis
Authors: Olędzka Ilona , Kowalski Piotr , Plenis Alina , Bączek Tomasz
Published: March 2017

The goal of this study was to assess various analytical approaches for the simultaneous and efficient extraction of steroid hormones (cortisone, cortisol, prednisolone, corticosterone, testosterone, 17α‐methyltestosterone, epitestosterone, progesterone) from urine samples prior to separation based on field‐amplified sample stacking MEKC (FASS‐MEKC). FASS‐MEKC successfully allowed the compounds to be separated within 12 min using a BGE composed of 5 mM sodium tetraborate, 150 mM boric acid, 50 mM SDS, and 15% methanol. Therefore, many procedures such as solid‐phase microextraction, SPE, and dispersive liquid–liquid microextraction (DLLME) were tested and compared using a multivariate tool, namely, cluster analysis. Finally, DLLME‐FASS‐MEKC was validated and proved a good linearity of calibration curves (R2 above 0.9948) in a concentration range from 50 to 1000 ng/mL for all analytes. The LOD was established at 15 ng/mL, whereas the LOQ was 50 ng/mL. The intra‐ and interday precision, expressed as RSD%, did not exceed 9.97%. The DLLME‐FASS‐MEKC method was successfully applied to the analysis of urine samples from healthy volunteers and sportsmen. This methodology could prove to be useful in clinical studies and/or doping control depending on the steroid concentrations required in biomedical applications.
Capillary‐assisted bipolar electrochemistry: A focused mini review
Authors: Bouffier Laurent , Sojic Neso , Kuhn Alexander
Published: March 2017

A bipolar electrode is quite unconventional as it behaves simultaneously as an anode and a cathode in contrast to a classic electrochemical setup where the electron transfer reactions are promoted on two different electrodes. The driving force is the polarization potential established between the solution and the bipolar electrode, that allows a wireless electrochemical addressing. In the past decade or so, bipolar electrochemistry has encountered a remarkable renewal of interest with extraordinary potentialities ranging from materials science to analytical chemistry. For practical reasons, bipolar electrochemistry experiments are very often performed in handmade electrochemical cells comprising tubes or capillaries. This review is focused on specific applications based on such types of experimental setups, from the macroscale where the tube acts only as an ordinary container down to the microscale where specific properties of the capillary come also into play.
Fast pyrolysis of coffee ground in a tilted‐slide reactor and characteristics of biocrude oil
Authors: Choi Yeon Seok , Choi Sang Kyu , Kim Seock Joon , Jeong Yeon Woo , Soysa Ramesh , Rahman Tawsif
Published: March 2017

Coffee grounds are considered to be a promising biomass resource due to the growth of coffee consumption and their high calorific value. In this study, we produced biocrude oil from coffee grounds in a tilted‐slide reactor, which has been previously used for the fast pyrolysis of woody biomass. Various pyrolysis temperatures were tested and the maximum biocrude oil yield was 59% at the pyrolysis temperature of 550°C with a feeding rate of coffee grounds at 17.7 kg/h. In a multistage condenser, the biocrude oil yields and properties were different in each condenser stage. The higher heating value of the biocrude oil from the primary condenser was 7,157 kcal/kg, which was about 60% higher than that from woody biomass. A phase separation was observed when the biocrude oil was stored at the atmospheric condition, and the biocrude oil viscosity became quite larger than that from woody biomass, which could even impede its flow. The viscosity decreased with increasing temperature and was more sensitive to temperature variations at lower temperatures. Mixing of ethanol also significantly improved viscosity characteristics. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 655–661, 2017
Analysis on the regional difference and impact factors of CO2 emissions in China
Authors: Cui Erqian , Ren Lijun , Sun Haoyu
Published: March 2017

China has become the largest CO2 emitter in the world for the rapid economic growth, and the large amount of CO2 emissions has caused worldwide concern. Based on the energy‐related data of CO2 emissions in eight economic zones from 2000 to 2012, this paper built a STIRPAT‐based multivariate linear model fitted by a ridge regression to examine the relationships between net CO2 emissions and a list of socioeconomic factors, including GDP per capita, population, energy intensity, and urbanization level. Regression results show that population, GDP per capita and urbanization level contribute to the increase of net CO2 emissions while energy intensity expresses an inhibitory effect. In addition, the elastic coefficients of different variables indicate that population scale and urbanization level play more important roles than GDP per capita and energy intensity in net CO2 emissions, where population scale contributes most significantly. Since the influence mechanisms of impact factors vary with scales of regional economy and characteristics of industry structure, some specific policy suggestions are also presented on how to mitigate the growth of CO2 emissions in each economic zone. This study have an important reference value for examining the impact factors of energy‐related CO2 emissions and the academic value in terms of enriching low carbon economy research systems in China. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1282–1289, 2017
Improving bank erosion modelling at catchment scale by incorporating temporal and spatial variability
Authors: Janes Victoria , Holman Ian , Birkinshaw Stephen , O'Donnell Greg , Kilsby Chris
Published: March 2017

Bank erosion can contribute a significant portion of the sediment budget within temperate catchments, yet few catchment scale models include an explicit representation of bank erosion processes. Furthermore, representation is often simplistic resulting in an inability to capture realistic spatial and temporal variability in simulated bank erosion. In this study, the sediment component of the catchment scale model SHETRAN is developed to incorporate key factors influencing the spatio‐temporal rate of bank erosion, due to the effects of channel sinuosity and channel bank vegetation. The model is applied to the Eden catchment, north‐west England, and validated using data derived from a GIS methodology. The developed model simulates magnitudes of total catchment annual bank erosion (617–4063 t y‐1) within the range of observed values (211–4426 t yr‐1). In addition, the model provides both greater inter‐annual and spatial variability of bank eroded sediment generation when compared with the basic model, and indicates a potential 61% increase of bank eroded sediment as a result of temporal flood clustering. The approach developed within this study can be used within a number of distributed hydrologic models and has general applicability to temperate catchments, yet further development of model representation of bank erosion processes is required. © 2017 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.
Partitioning of nanoparticle-originated dissolved silver in natural and artificial sediments
Authors: Rajala Juho E. , Vehniäinen Eeva-Riikka , Väisänen Ari , Kukkonen Jussi V.K.
Published: March 2017

Sediments are believed to be a major sink for silver nanoparticles (AgNPs) in the aquatic environment, but there is a lack of knowledge about the environmental effects and behavior of AgNPs in sediments. The release of highly toxic Ag+ through dissolution of AgNPs is one mechanism leading to toxic effects in sediments. We applied an ultrasound-assisted sequential extraction method to evaluate the dissolution of AgNPs and to study the partitioning of dissolved Ag in sediments. Silver was spiked into artificial and 2 natural sediments (Lake Höytiäinen sediment and Lake Kuorinka sediment) as silver nitrate (AgNO3), uncoated AgNPs, or polyvinylpyrrolidone-coated AgNPs (PVP-AgNPs). In addition, the total body burdens of Ag in the sediment-dwelling oligochaete Lumbriculus variegatus were assessed over a 28-d exposure period. The dissolution rate was found to be similar between the uncoated AgNP and PVP-AgNP groups. In all sediments, dissolved Ag was mainly bound to the residual fraction of the sediment, followed by iron and manganese oxides or natural organic matter. In Lake Kuorinka sediment, dissolved Ag that originated from PVP-AgNPs was relatively more bioaccessible, also resulting in higher total body burden in L. variegatus than that from uncoated AgNPs or AgNO3. In artificial sediment and Lake Höytiäinen sediment, AgNO3 was significantly more bioaccessible than AgNPs. Our results highlight the importance of sediment properties and AgNP surface chemistry when evaluating the environmental exposure of AgNPs. Environ Toxicol Chem 2017;36:2593–2601. © 2017 SETAC
Overlay spectrum sharing for device‐to‐device communications in two‐way cellular networks with nodes mobility
Authors: Gurjar Devendra Singh , Upadhyay Prabhat Kumar
Published: March 2017

In this paper, we propose and investigate a three‐phase overlay spectrum‐sharing scheme for device‐to‐device (D2D) communications in a bidirectional cellular network with nodes mobility. In this scheme, a pair of D2D users facilitates relaying to the cellular nodes (base station and mobile user), and in return, they get the opportunity to exchange their own information by exploiting the same cellular spectrum. With this, the two end‐to‐end bidirectional communications (D2D and cellular) can be realized in three time phases by using selection‐combining technique at both cellular nodes and decode‐and‐forward (DF) relaying scheme at both participating D2D users. For DF operation, we consider two strategies, namely, exclusive‐OR (XOR)‐based DF, and superposition‐based DF. All the channels are assumed to be time varying, and Markovian model is used to characterize the impact of nodes mobility. For this set‐up, we first derive the outage probability for both cellular and D2D links under Rayleigh fading. Then, we obtain the asymptotic expressions of outage probability for both systems and used them further to reveal the critical value of power‐splitting factor for spectrum sharing. Above all, we acquire the expression of average system throughput to perform a fair performance comparison with the other existing schemes.