bluuebunny/crossref_metadata_2025 huggingface dataset:
FPA-FTIR Microspectroscopy for Monitoring Chemotherapy Efficacy in Triple-Negative Breast Cancer
Authors: Zawlik Izabela , Kaznowska Ewa , Cebulski Jozef , Kolodziej Magdalena , Depciuch Joanna , Vongsvivut Jitraporn , Cholewa Marian
Published: November 2016

Triple-negative breast cancer is the most aggressive breast cancer subtype with limited treatment options and a poor prognosis. Approximately 70% of triple-negative breast cancer patients fail to achieve a pathologic complete response (pCR) after chemotherapy due to the lack of targeted therapies for this subtype. We report here the development of a focal-plane-array Fourier transform infrared (FPA-FTIR) microspectroscopic technique combined with principal component analysis (PCA) for monitoring chemotherapy effects in triple-negative breast cancer patients. The PCA results obtained using the FPA-FTIR spectral data collected from the same patients before and after the chemotherapy revealed discriminatory features that were consistent with the pathologic and clinical responses to chemotherapy, indicating the potential of the technique as a monitoring tool for observing chemotherapy efficacy.
Simulated ischemia/reperfusion-induced p65-Beclin 1-dependent autophagic cell death in human umbilical vein endothelial cells
Authors: Zeng Min , Wei Xin , Wu Zhiyong , Li Wei , Zheng Yin , Li Bing , Meng Xuqing , Fu Xiuhong , Fei Yi
Published: November 2016

Myocardial ischemia/reperfusion (I/R) injury detrimentally alters the prognosis of patients undergoing revascularization after acute myocardial infarction. Our previous study demonstrated that NF-κB-induced autophagy plays a detrimental role in cardiac I/R injury using a rabbit myocardial I/R model. In this study, we sought to explore the specific mechanism of this autophagy-mediated cell damage in an in vitro simulated ischemia/reperfusion (sI/R) model using human umbilical vein endothelial cells. Our current study demonstrates that simulated I/R induces autophagy in a p65-Beclin 1-dependent manner, which can be suppressed with the inhibition of NF-κB. Furthermore, rapamycin which promotes autophagy, exacerbates sI/R-induced cell death. While 3-methyladenine rescues cell damage. Our data thus suggest that I/R promotes NF-κB p65 activity mediated Beclin 1-mediated autophagic flux, thereby exacerbating myocardial injury.
Quantitative identification of dynamical transitions in a semiconductor laser with optical feedback
Authors: Quintero-Quiroz C. , Tiana-Alsina J. , Romà J. , Torrent M. C. , Masoller C.
Published: November 2016

Identifying transitions to complex dynamical regimes is a fundamental open problem with many practical applications. Semi- conductor lasers with optical feedback are excellent testbeds for studying such transitions, as they can generate a rich variety of output signals. Here we apply three analysis tools to quantify various aspects of the dynamical transitions that occur as the laser pump current increases. These tools allow to quantitatively detect the onset of two different regimes, low-frequency fluctuations and coherence collapse, and can be used for identifying the operating conditions that result in specific dynamical properties of the laser output. These tools can also be valuable for analyzing regime transitions in other complex systems.
Evaluating renewable natural resources flow and net primary productivity with a GIS-Emergy approach: A case study of Hokkaido, Japan
Authors: Wang Chengdong , Zhang Shenyan , Yan Wanglin , Wang Renqing , Liu Jian , Wang Yutao
Published: November 2016

Renewable natural resources, such as solar radiation, rainfall, wind, and geothermal heat, together with ecosystem services, provide the elementary supports for the sustainable development of human society. To improve regional sustainability, we studied the spatial distributions and quantities of renewable natural resources and net primary productivity (NPP) in Hokkaido, which is the second largest island of Japan. With the help of Geographic Information System (GIS) software, distribution maps for each type of renewable natural resource were generated by kriging interpolation based on statistical records. A composite map of the flow of all types of renewable natural resources was also generated by map layer overlapping. Additionally, we utilized emergy analysis to convert each renewable flow with different attributes into a unified unit (i.e., solar equivalent joules [sej]). As a result, the spatial distributions of the flow of renewable natural resources of the Hokkaido region are presented in the form of thematic emergy maps. Thus, the areas with higher renewable emergy can be easily visualized and identified. The dominant renewable flow in certain areas can also be directly distinguished. The results can provide useful information for regional sustainable development, environmental conservation and ecological management.
Charge storage mechanisms of manganese oxide nanosheets and N-doped reduced graphene oxide aerogel for high-performance asymmetric supercapacitors
Authors: Iamprasertkun Pawin , Krittayavathananon Atiweena , Seubsai Anusorn , Chanlek Narong , Kidkhunthod Pinit , Sangthong Winyoo , Maensiri Santi , Yimnirun Rattikorn , Nilmoung Sukanya , Pannopard Panvika , Ittisanronnachai Somlak , Kongpatpanich Kanokwan , Limtrakul Jumras , Sawangphruk Montree
Published: November 2016

Although manganese oxide- and graphene-based supercapacitors have been widely studied, their charge storage mechanisms are not yet fully investigated. In this work, we have studied the charge storage mechanisms of K-birnassite MnO2 nanosheets and N-doped reduced graphene oxide aerogel (N-rGOae) using an in situ X-ray absorption spectroscopy (XAS) and an electrochemical quart crystal microbalance (EQCM). The oxidation number of Mn at the MnO2 electrode is +3.01 at 0 V vs. SCE for the charging process and gets oxidized to +3.12 at +0.8 V vs. SCE and then reduced back to +3.01 at 0 V vs. SCE for the discharging process. The mass change of solvated ions, inserted to the layers of MnO2 during the charging process is 7.4 μg cm−2. Whilst, the mass change of the solvated ions at the N-rGOae electrode is 8.4 μg cm−2. An asymmetric supercapacitor of MnO2//N-rGOae (CR2016) provides a maximum specific capacitance of ca. 467 F g−1 at 1 A g−1, a maximum specific power of 39 kW kg−1 and a specific energy of 40 Wh kg−1 with a wide working potential of 1.6 V and 93.2% capacity retention after 7,500 cycles. The MnO2//N-rGOae supercapacitor may be practically used in high power and energy applications.
Effects of climate and fire on short-term vegetation recovery in the boreal larch forests of Northeastern China
Authors: Liu Zhihua
Published: November 2016

Understanding the influence of climate variability and fire characteristics in shaping postfire vegetation recovery will help to predict future ecosystem trajectories in boreal forests. In this study, I asked: (1) which remotely-sensed vegetation index (VI) is a good proxy for vegetation recovery? and (2) what are the relative influences of climate and fire in controlling postfire vegetation recovery in a Siberian larch forest, a globally important but poorly understood ecosystem type? Analysis showed that the shortwave infrared (SWIR) VI is a good indicator of postfire vegetation recovery in boreal larch forests. A boosted regression tree analysis showed that postfire recovery was collectively controlled by processes that controlled seed availability, as well as by site conditions and climate variability. Fire severity and its spatial variability played a dominant role in determining vegetation recovery, indicating seed availability as the primary mechanism affecting postfire forest resilience. Environmental and immediate postfire climatic conditions appear to be less important, but interact strongly with fire severity to influence postfire recovery. If future warming and fire regimes manifest as expected in this region, seed limitation and climate-induced regeneration failure will become more prevalent and severe, which may cause forests to shift to alternative stable states.
Modulation of Biological Targets Using Allosteric Ligands: Food for Thought
Authors: Doller Dario , Huang Xinyan
Published: November 2016

Research in life sciences is witnessing the emergence of new knowledge at a greater pace than ever before. This is starting to translate into innovative therapeutic treatments and approaches. The use of chemicals to modify the course of human disease has evolved into a number of modalities, which may arbitrarily be classified as biologics or small-molecule treatments. Some of the characteristics of these two are compared and contrasted. The term “allosteric modulators” is generally used to describe small molecules that change the attributes of large biological macromolecules, such as membrane-bound receptors, ion channels and transporters, as well as soluble enzymes. The rationale that stimulated the research into allosteric drugs in the mid-1990’s is presented, including perspectives on the early learnings that have emerged such as “flat structure–activity relationships” and “functional switches”, and how subtle differences in mechanisms of allosteric modulation can impact drug discovery.
Molecular Biology Techniques Applied to GPCR Allosteric and Biased Ligands
Authors: Frauli Mélanie , Franchet Christel , Dorange Ismet , Mancini Arturo , Breton Billy , Schann Stephan
Published: November 2016

G-protein-coupled receptors (GPCRs) have proven to be highly successful therapeutic targets, representing more than 40% of the top 200 worldwide best-selling drugs, and are projected to represent 120 billion US dollars of revenues per year by 2017. Interestingly, these marketed compounds modulate the activity of a restricted set of 100 GPCRs out of the 350 that are considered to be potential drug targets, indicating that in spite of the powerful drug discovery arsenal that is now available, it remains hard to “crack” new GPCRs. This is probably due to the inherent complexity of GPCR signaling, that arises from the multiplicity of intracellular pathways that can be elicited by a single receptor, according to the downstream effectors it is interacting with. To overcome these obstacles, an interesting strategy has emerged targeting allosteric modulator (AM) sites. This chapter reviews current technologies used for AM high-throughput screening (HTS) and signaling characterization, as well as the utility of combining novel approaches to efficiently discover and characterize their ability to activate or inhibit specific signaling pathways.
Positive Allosteric Modulators of Opioid Receptors
Authors: Rockwell Kristin L. , Alt Andrew
Published: November 2016

Activation of opioid receptors produces powerful analgesia; and µ-opioid receptor agonists such as morphine and oxycodone remain the “gold standard” for pain therapy, despite their abuse liability and dangerous side effect profile. Safer pain medications are urgently needed. The recent discovery of positive allosteric modulators (PAMs) of µ- and δ-opioid receptors provides a new approach for exploiting the analgesic effects of opioid receptor activation. PAMs enhance endogenous opioid signaling but do not activate the receptor directly, and therefore may be expected to exert analgesic effects while improving upon the side effect profile and abuse liability associated with direct-acting opioid agonists. The discovery and characterization of the first opioid PAM molecules is described, as well as the rationale for the development of opioid PAMs as novel therapeutic agents for the treatment of pain.
mGlu4 PET Ligands as Enablers of Target Biology Understanding
Authors: Zhang Zhaoda , Poutiainen Pekka , Brownell Anna-Liisa
Published: November 2016

Identifying the biological origin of a disease and the potential targets for intervention are some of the first steps in the discovery of a medicine. The metabotropic glutamate receptor 4 (mGlu4) has lately received much attention due to its potential role in various neuronal diseases such as Parkinson’s disease (PD) and other disorders. To better understand the role of mGlu4 in health and disease conditions, we were interested in developing an mGlu4-selective radiotracer for in vivo studies. Herein we discuss our efforts to develop novel mGlu4 positron emission tomography (PET) radiotracers from mGlu4 positive allosteric modulators (PAMs). We have investigated the biology of this receptor in vitro using cells expressing mGlu4, as well as in vivo, using the 6-hydroxydopamine (6-OHDA)-lesion rat model of Parkinson’s disease. Results of cell studies showed the important role of endogenous glutamate in inducing changes in the affinity of allosteric modulators of mGlus. Results from PET imaging studies showed the interplay between presynaptic mGlu4 and postsynaptic mGlu5 expression in the lesioned side of the brain, while the results of pharmacological MRI studies of the hemodynamic response showed enhanced signal changes in cortical areas in the lesioned side after challenge with mGlu4 PAMs or mGlu5 negative allosteric monitors (NAMs).
Allosteric Modulators of Adenosine, P2Y and P2X Receptors
Authors: Jacobson Kenneth A. , Gao Zhan-Guo
Published: November 2016

Allosteric modulators of purine and pyrimidine receptors modulate the activity of endogenous (orthosteric) agonists, for example, as protective signals in various organs and tissues under stress or in disease states, and often are more receptor-subtype-selective than orthosteric ligands. Structure–activity relationships (SARs) of positive allosteric modulators (PAMs) acting at A1 or A3 adenosine receptors (ARs) have been probed, and negative allosteric modulators (NAMs) have been reported for the ARs. The classes of benzoylthiophenes and related heterocycles have provided numerous A1AR PAMs, which are envisioned for the treatment of chronic pain. Bitopic PAM–agonists of the A1AR have been designed. Most PAMs of the A3AR, including LUF6000 and LUF6096, come from three classes of substituted heterocycles: 3-(2-pyridinyl)isoquinolines, 2,4-disubstituted quinolines and 1H-imidazo-[4,5-c]quinolin-4-amines. The binding sites of these PAMs have been probed using site-directed mutagenesis of the ARs. Various small molecules, such as ivermectin and tanshinone IIA sulfonate, that inhibit or enhance action at the P2X ligand-gated ion channels, respectively, are now thought to be allosteric modulators. Only a few PAMs and NAMs are known for the G-protein-coupled P2Y receptors (P2YRs) for nucleotides. A P2Y1R X-ray crystallographic structure identified an allosteric binding site of a potent and selective urea antagonist 1-(2-(2-tert-butylphenoxy)pyridin-3-yl)-3-(4-(trifluoromethoxy)phenyl)urea (BPTU), an antithrombotic agent, as completely distinct from the nucleotide binding site, instead located on the outer periphery of the receptor, in contact with the phospholipid bilayer. This is a novel location for an allosteric modulator within the family of G-protein-coupled receptors.
Positive Allosteric Modulators of G-Protein-Coupled Receptors that Act via Covalent Mechanisms of Action
Authors: Nolte Whitney M. , Carpino Philip A.
Published: November 2016

Positive allosteric modulators (PAMs) of G-protein-coupled receptors (GPCRs) potentiate the activity of ligands that act at orthosteric sites on the receptors. While the majority of GPCR PAMs bind reversibly to allosteric sites on receptors to induce conformational changes that alter binding affinity and/or efficacy, several examples of PAMs that bind irreversibly to GPCRs have recently been identified. These PAMs, part of a new class of drugs known as covalent PAMs (cPAMs) of GPCRs, contain electrophilic groups which can react with thiol nucleophiles. Two representative cPAMs, 6,7-dichloro-2-methylsulfonyl-3-tert-butylaminoquinoxaline (historically known as “compound 2”) and 4-(3-benzyloxyphenyl)-2-ethylsulfinyl-6-(trifluoromethyl)pyrimidine (BETP), were shown to potentiate second messenger signaling activity (i.e., cAMP accumulation) of several peptides at the glucagon-like peptide-1 receptor (GLP-1R) by reacting with a cysteine residue in the third intracellular loop of GLP-1R. BETP was also found to potentiate the actions of peptides at a variant of the glucagon receptor (GCGR), a receptor with high homology to GLP-1R, when a single phenylalanine residue at position 345 was replaced by a cysteine residue for covalent modification. Herein, we review the pharmacological studies of cPAMs of GLP-1R and a glucagon receptor variant (Phe345Cys GCGR) and summarize studies that resulted in the discovery of their covalent mechanism of action.
Allosteric Modulators of Heat Shock Protein 90 (HSP90)
Authors: Koay Yen Chin , McAlpine Shelli
Published: November 2016

Heat shock proteins (HSP) are a family of molecular chaperones that are the most conserved proteins present in both prokaryotes and eukaryotes. HSPs facilitate numerous events in cellular physiology including: protein recycling, transportation, migration, post-translational modification, and the regulation of signalling pathways. The molecular chaperone heat shock protein 90 (HSP90) plays a particularly important role in maintaining homeostasis. As a highly conserved molecular chaperone, HSP90 is an abundant and ubiquitously expressed protein, constituting 1–2% of total cellular protein in normal cells. In order to protect mutated and over-expressed oncoproteins from degradation, HSP90 increases to 3–6% of overall protein in cancerous cells. HSP90 is also a key regulator of the stress response, in part because it folds, maintains, and stabilizes over 400 client proteins, many of which are involved in cancer cell growth. This chapter compares and contrasts three classes of allosteric inhibitors. The first class are compounds targeting the ATP binding site at the N-terminus of HSP90 (classical inhibitors), while impacting clients that bind to the middle domain. The second class are those that bind to the C-terminus, which have anti-cancer cellular activity without inducing high levels of HSF-1, HSP70, or HSP27. The third class are the SM series, binding between the N- and middle domains of HSP90 but impacting the C-terminus. Progress made and challenges associated with each class of ligands are discussed.
Superior rate capability of a sulfur composite cathode in a tris(trimethylsilyl)borate-containing functional electrolyte
Authors: Wang Lina , Li Qinyu , Yang Huijun , Yang Jun , Nuli Yanna , Wang Jiulin
Published: November 2016

A trace of TMSB additive in the electrolyte remarkably boosts the high rate capability of a sulfur composite cathode.
Ultrafast chiral separations for high throughput enantiopurity analysis
Authors: Barhate Chandan L. , Joyce Leo A. , Makarov Alexey A. , Zawatzky Kerstin , Bernardoni Frank , Schafer Wes A. , Armstrong Daniel W. , Welch Christopher J. , Regalado Erik L.
Published: November 2016

Ultrafast chiral chromatography enables high throughput enantiopurity analysis (over one thousand samples in an 8 h workday) for enantioselective synthesis investigations.
Thermal decomposition of ammonium hexachloroosmate
Authors: Asanova T. I. , Kantor I. , Asanov I. P. , Korenev S. V. , Yusenko K. V.
Published: November 2016

A one-step mechanism of the thermal decomposition of (NH4)2[OsCl6] suggested previously proves to be unworkable under a time-resolved ED XAFS and PXRD study.
Role of lanthanum species in improving the photocatalytic activity of titanium dioxide
Authors: Siah Wai Ruu , Lintang Hendrik O. , Yuliati Leny
Published: November 2016

Lanthanum modification resulted in the additional formation of Ti3+ states, which enhanced the charge transfer and separation. Consequently, the photocatalytic activity of TiO2 under UV light irradiation was significantly improved.
Monomeric Ti(iv)-based complexes incorporating luminescent nitrogen ligands: synthesis, structural characterization, emission spectroscopy and cytotoxic activities
Authors: Khalil Georges , Orvain Christophe , Fang Lu , Barloy Laurent , Chaumont Alain , Gaiddon Christian , Henry Marc , Kyritsakas Nathalie , Mobian Pierre
Published: November 2016

Novel photoluminescent 2,2′-bipyrimidine ligands and their titanium(iv) complexes are cytotoxic.
Visible light driven mesoporous Ag-embedded ZnO nanocomposites: reactive oxygen species enhanced photocatalysis, bacterial inhibition and photodynamic therapy
Authors: Gupta Jagriti , Mohapatra Jeotikanta , Bahadur D.
Published: November 2016

The systemic diagram shows the mechanism of photocatalysis, bacterial inhibition and photodynamic therapy through the generation of reactive oxygen species.
A scalable in situ surfactant-free synthesis of a uniform MnO/graphene composite for highly reversible lithium storage
Authors: Cai Wenlong , Li Gaoran , Zhang Kailong , Zhou Jianbin , Qian Yitai , Du Jin
Published: November 2016

A scalable in situ surfactant-free synthesis of a uniform MnO/graphene composite was prepared, and exhibited large reversible capacity with long-term and superior rate performance.
Self-polymerized dopamine as an organic cathode for Li- and Na-ion batteries
Authors: Liu Tianyuan , Kim Ki Chul , Lee Byeongyong , Chen Zhongming , Noda Suguru , Jang Seung Soon , Lee Seung Woo
Published: November 2016

Redox-active, self-polymerized dopamine shows promise as organic cathode materials for Li- and Na-ion batteries.
Influence of chemical speciation and biofilm composition on mercury accumulation by freshwater biofilms
Authors: Dranguet P. , Le Faucheur S. , Cosio C. , Slaveykova V. I.
Published: November 2016

Biofilm mercury accumulation and composition are potential bioindicators of Hg exposure in contaminated sites.
Electrochemical behavior of a membrane based on zirconium(iv) phosphoborate nanocomposite and its application in dye removal
Authors: Kaushal Sandeep , Badru Rahul , Kumar Sanjeev , Sharma Pushpender K. , Mittal Susheel K. , Singh Pritpal
Published: November 2016

A new hybrid ion-exchange membrane was prepared from a novel composite obtained by dispersion of polyaniline into an inorganic matrix of zirconium(iv) phosphoborate employing a sol–gel method.
One-step fabrication of silica colloidosomes with in situ drug encapsulation
Authors: Su Yechao , Zhao Hong , Wu Jinrong , Xu Jianhong
Published: November 2016

In situ modification, drug encapsulation and fabrication of hollow silica colloidosomes in microfluidic device.
C-Phycocyanin as a potential biosensor for heavy metals like Hg2+ in aquatic systems
Authors: Bhayani Khushbu , Mitra Madhusree , Ghosh Tonmoy , Mishra Sandhya
Published: November 2016

Fluorescence quenching ability of C-phycocyanin (CPC) as a biosensor for detection of Hg2+ in lower concentrations (μM) in aquatic environment.
Promising bulk nanostructured Cu2Se thermoelectrics via high throughput and rapid chemical synthesis
Authors: Tafti Mohsen Y. , Ballikaya Sedat , Khachatourian Adrine Malek , Noroozi Mohammad , Saleemi Mohsin , Han Li , Nong Ngo V. , Bailey Trevor , Uher Ctirad , Toprak Muhammet S.
Published: November 2016

Bulk nano-Cu2Se with low thermal conductivity and high thermoelectric efficiency was fabricated via a facile and high yield synthesis route.
Preparation and characterization of silicone rubber cured via catalyst-free aza-Michael reaction
Authors: Feng Linglong , Zhou Lin , Feng Shengyu
Published: November 2016

A novel silicone rubber of high strength and stable dimension was cured via catalyst-free aza-Michael reaction.
Rhenium(i) complexes with phenanthrolines bearing electron-withdrawing Cl and electron-donating CH3substituents – synthesis, photophysical, thermal, and electrochemical properties with electroluminescence ability
Authors: Świtlicka Anna , Klemens Tomasz , Machura Barbara , Schab-Balcerzak Ewa , Laba Katarzyna , Lapkowski Mieczyslaw , Grucela Marzena , Nycz Jacek , Szala Marcin , Kania Magdalena
Published: November 2016

Substituent effect was investigated.
Effect of pore-directing agents and silanol groups in mesoporous silica nanoparticles as Nafion fillers on the performance of DMFCs
Authors: Yang Ciao-Wei , Chen Kuei-Hsien , Cheng Soofin
Published: November 2016

Pore-directing agents in SBA-15 and MSN mesopores could resist methanol crossover, while only P123 inside SBA-15 could assist proton transferring. But, highest proton conductivity was obtained on membranes with extracted MSN of high silanol contents.
Synthesis and characterization of magnetic copper–iron-titanate and uptake studies of americium from nuclear waste solutions
Authors: Muthukumar Krishnan , Lakshmi D. Shanthana , Gujar Rajesh B. , Boricha Arvind B. , Mohapatra Prasanta K. , Bajaj Hari C.
Published: November 2016

Magnetic materials, which find enormous applications due to their benign nature, can have their efficiency and stability enhanced by incorporation of foreign materials and controlling the synthesis conditions.
N-Substituted poly(3,6-dithienylcarbazole) derivatives: a new class of redox-active electrode materials for high-performance flexible solid-state pseudocapacitors
Authors: Yiğit Deniz , Güllü Mustafa
Published: November 2016

This study presents the design, synthesis and charge storage features of novel poly(3,6-dithienylcarbazole) derivatives as redox-active materials for high performance energy storage applications.
The Pharyngostomy Tube: Indications, Technique, Efficacy, and Safety in Modern Surgical Practice
Authors: Berger Jonathan , Andrade Rafael , Podgaetz Eitan , Garza-Castillon Rafael
Published: November 2016

Background Long-term nasogastric tubes are uncomfortable and associated with complications such as impairment with speech and swallowing, septum trauma, epistaxis, alar necrosis, and intubation of the trachea among others. Pharyngostomy tubes (PTs) are an alternative for prolonged enteral feeding, transluminal drainage of collections, and gastric decompression in patients with an intestinal obstruction and an inoperable abdomen.

Patients and Methods This is a retrospective analysis of patients who had a PT placed at our institution from May 2005 to March 2015. The primary end point of the study was to establish the type and rate of complications and aspiration events related to PT use.

Results During the specified period, a total of 84 PTs were placed. The most common indication for PT placement was enteric decompression in 65 (77.4%), followed by transluminal collection drainage in 12 (14.3%), and enteral access for nutrition in 7 (8.3%) patients. The mean time to tube removal was 17.8 days ± 17.1 (range, 2–119). We encountered 10 (11.2%) complications related to PT placement, including 7 cases of cellulitis, 2 superficial abscesses, and 1 patient with pharyngeal hemorrhage.

Conclusion PTs are a relatively simple, safe, and straightforward approach to achieve long-term enteral decompression, access for feeding or transluminal drainage, avoiding the complications associated with prolonged nasogastric tube placement. The complication rate is low and patient satisfaction and compliance appear to be higher than with nasogastric tubes. Modern surgeons should be familiar with the procedure and technique. PTs should be part of every surgeon's armamentarium.
Minimally Invasive Spine Surgery for Unstable Thoracolumbar Burst Fractures: A Case Series
Authors: Agarwal Nitin , Choi Phillip , Sekula Raymond
Published: November 2016

Introduction Traumatic thoracolumbar burst fracture is a common pathology without a clear consensus on best treatment approach. Minimally invasive approaches are being investigated due to potential benefits in recovery time and morbidity. We examine long-term resolution of symptoms of traumatic thoracolumbar burst fractures treated with percutaneous posterior pedicle screw fixation.

Methods Retrospective clinical review of seven patients with spinal trauma who presented with thoracolumbar burst fracture from July 2012 to April 2013 and were treated with percutaneous pedicle screw fixation. Electronic patient charts and radiographic imaging were reviewed for initial presentation, fracture characteristics, operative treatment, and postoperative course.

Results The patients had a median age of 29 years (range 18 to 57), and 57% were men. The median Thoracolumbar Injury Classification and Severity Scale score was 4 (range 2 to 9). All patients had proper screw placement and uneventful postoperative courses given the severity of their individual traumas. Five of seven patients were reached for long-term follow-up of greater than 28 months. Six of seven patients had excellent pain control and stability at their last follow-up. One patient required revision surgery for noncatastrophic hardware failure.

Conclusion Percutaneous pedicle screw fixation for the treatment of unstable thoracolumbar burst fracture may provide patients with durable benefits and warrants further investigation.
A prospective study of patient safety incidents in gastrointestinal endoscopy
Authors: Matharoo Manmeet , Haycock Adam , Sevdalis Nick , Thomas-Gibson Siwan
Published: November 2016

Background and study aims Medical error occurs frequently with significant morbidity and mortality. This study aime to assess the frequency and type of endoscopy patient safety incidents (PSIs).

Patients and methods A prospective observational study of PSIs in routine diagnostic and therapeutic endoscopy was undertaken in a secondary and tertiary care center. Observations were undertaken within the endoscopy suite across pre-procedure, intra-procedure and post-procedure phases of care. Experienced (Consultant-level) and trainee endoscopists from medical, surgical, and nursing specialities were included. PSIs were defined as any safety issue that had the potential to or directly adversely affected patient care: PSIs included near misses, complications, adverse events and “never events”. PSIs were reviewed by an expert panel and categorized for severity and nature via expert consensus.

Results One hundred and forty procedures (92 diagnostic, 48 therapeutic) over 37 lists (experienced operators n = 25, trainees n = 12) were analyzed. One hundred forty PSIs were identified (median 1 per procedure, range 0 – 7). Eighty-six PSIs (61 %) occurred in 48 therapeutic procedures. Zero PSIs were detected in 13 diagnostic procedures. 21 (15 %) PSIs were categorized as severe and 12 (9 %) had the potential to be “never events,” including patient misidentification and wrong procedure. Forty PSIs (28 %) were of intermediate severity and 78 (56 %) were minor. Oxygen monitoring PSIs occurred most frequently.

Conclusion This is the first study documenting the range and frequency of PSIs in endoscopy. Although many errors are minor without immediate consequence, further work should identify whether prevention of such recurrent errors affects the incidence of severe errors, thus improving safety and quality.
The KINGS of Africa’s Digital Economy
Authors: Osiakwan Eric M.K.
Published: November 2016

The twentieth century saw the economic rise of Asia through the significant economic rise of the “Asian Tiger” countries (Kojima 2000; UNCTAD 1996). But the twenty-first century has been dubbed the African century (Wikipedia 2016). Tech Crunch, renowned technology media company, recently published an article entitled “The Future Is African” (Nash 2015), which aptly described how Africa is unleashing innovation by combining mobile and Web technology to lead the world in the twenty-first century.
Reimagine What You Already Know: Toward New Solutions to Longstanding Problems
Authors: Larson Jay , Munger Michael
Published: November 2016

Knowledge and technology can combine to change societies dramatically, creating opportunities that were previously unthinkable. Many African nations now stand at the threshold of revolutionary changes based on information communication technologies (ICTs). Instead of painstakingly developing traditional banking, education, and other sectors—with decades of wasted human lives and opportunities—introducing mobile technology has put completely new solutions into the hands of a new generation. Some of the key elements of these new solutions are in education, the backbone for innovation and economic development. Although innovators are seeking new ways to educate the next generation, the problem of delivering adequate educational services to those without the means to afford expensive private schools is still a critical problem. We suggest that education must be reimagined, very nearly from the ground up. Once people take education out of the four walls of the traditional classroom into homes, libraries, internet cafés, and city streets, a completely new learning experience is imaginable—an experience that innovators need to harness now in order to transform the way in which education is delivered in Africa. Students in the “digital” school will decide what, where, and when to learn. We need these digital models to start reimagining education in Africa. We offer reimaginings of several elements in the education sector, including school management, the classroom, the learning experience, and certification.
Building ICT Entrepreneurship Ecosystems in Resource-Scarce Contexts: Learnings from Kenya’s “Silicon Savannah”
Authors: Bramann Johannes Ulrich
Published: November 2016

Establishing information and communications technology (ICT) entrepreneurship ecosystems in resource-scarce contexts is difficult because these contexts lack important preconditions, such as financial resources, established ICT sectors, and relevant human capital. Current theoretical perspectives and policy prescriptions about them stem mainly from the Global North and provide little insight into how to establish these conditions “from scratch.” In 2016, numerous African countries are looking toward the continent’s ICT vanguard, Kenya, and its gradually maturing “Silicon Savannah,” asking themselves, “How did they do it?”

This chapter will shed light on the evolution of Kenya’s ICT ecosystem and explore the barriers and subsequent enabling processes encountered when growing an ICT ecosystem in a resource-scarce context. The insights offered here were developed over three years of doctoral research and especially through four months of qualitative research in Nairobi in 2013. The chapter provides a holistic perspective on the barriers and enablers encountered in the areas of culture, human capital, finance, policy, entrepreneurial support systems, and markets. Together with relevant theory on how ecosystems emerge and develop, these insights will be used to propose a model that explains how ICT ecosystems can emerge in resource-scarce contexts. The model shows how locally available enabling processes can be drawn on to substitute and establish the missing condition factors. Entrepreneurship support institutions, for example, emerged as pivotal enablers that can kick-start industry emergence processes, train human capital, and help establish conducive sociocultural norms. Further, the creation of initial market demand through developmental stakeholders and the inflow of expatriate entrepreneurs also emerged as enablers. The chapter ends with a call for critically needed research and specific recommendations for development stakeholders, governments, and practitioners in tackling current barriers in order to help develop ecosystems in resource-scarce countries beyond their nascent phase.
Generation and dynamics analysis of N-scrolls existence in new translation-type chaotic systems
Authors: Liu Yue , Guo Shuxu
Published: November 2016

In this paper, we propose two kinds of translation type chaotic systems for creating 2 N + 1-and 2(N + 1)-scrolls chaotic attractors from a simple three-dimensional system, which are named the translation-2 chaotic system (a12a21 < 0) and the translation-3 chaotic system (a12a21 > 0). We also propose the successful design criterion for constructing 2 N + 1-and 2(N + 1)-scrolls, respectively. Then, the dynamics property of the translation-2 chaotic system is studied in detail. MATLAB simulation results show that very sophisticated dynamical behaviors and unique chaotic behaviors of the system. Finally, the definition and criterion of multi-scroll attractors for the translation-3 chaotic system is obtained. Three representative examples are shown in some classical chaotic systems that can be equally obtained via the set parameters of the translation type chaotic system. Furthermore, we show that the translation type chaotic systems have similar but topologically non-equivalent chaotic attractors, and they are the three-dimensional ordinary differential equations.
Non-adiabatic transition probability dependence on conical intersection topography
Authors: Malhado João Pedro , Hynes James T.
Published: November 2016

We derive a closed form analytical expression for the non-adiabatic transition probability for a distribution of trajectories passing through a generic conical intersection (CI), based on the Landau-Zener equation for the non-adiabatic transition probability for a single straight-line trajectory in the CI’s vicinity. We investigate the non-adiabatic transition probability’s variation with topographical features and find, for the same crossing velocity, no intrinsic difference in efficiency at promoting non-adiabatic decay between peaked and sloped CIs, a result in contrast to the commonly held view. Any increased efficiency of peaked over sloped CIs is thus due to dynamical effects rather than to any increased transition probability of topographical origin. It is also shown that the transition probability depends in general on the direction of approach to the CI, and that the coordinates’ reduced mass can affect the transition probability via its influence on the CI topography in mass-scaled coordinates. The resulting predictions compare well with surface hopping simulation results.
Charge neutral MoS2 field effect transistors through oxygen plasma treatment
Authors: Dhall Rohan , Li Zhen , Kosmowska Ewa , Cronin Stephen B.
Published: November 2016

Lithographically fabricated MoS2 field effect transistors suffer from several critical imperfections, including low sub-threshold swings, large turn-on gate voltages (VT), and wide device-to-device variability. The large magnitude and variability of VT stems from unclean interfaces, trapped charges in the underlying substrate, and sulfur vacancies created during the mechanical exfoliation process. In this study, we demonstrate a simple and reliable oxygen plasma treatment, which mitigates the effects of unintentional doping created by surface defect sites, such as S vacancies, and surface contamination. This plasma treatment restores charge neutrality to the MoS2 and shifts the threshold turn-on voltage towards 0 V. Out of the 10 devices measured, all exhibit a shift of the FET turn-on voltage from an average of −18 V to −2 V. The oxygen plasma treatment passivates these defects, which reduces surface scattering, causing increased mobility and improved subthreshold swing. For as-prepared devices with low mobilities (∼0.01 cm2/V s), we observe up to a 190-fold increase in mobility after exposure to the oxygen plasma. Perhaps the most important aspect of this oxygen plasma treatment is that it reduces the device-to-device variability, which is a crucial factor in realizing any practical application of these devices.
Decay of geodesic acoustic modes due to the combined action of phase mixing and Landau damping
Authors: Biancalani A. , Palermo F. , Angioni C. , Bottino A. , Zonca F.
Published: November 2016

Geodesic acoustic modes (GAMs) are oscillations of the electric field whose importance in tokamak plasmas is due to their role in the regulation of turbulence. The linear collisionless damping of GAMs is investigated here by means of analytical theory and numerical simulations with the global gyrokinetic particle-in-cell code ORB5. The combined effect of the phase mixing and Landau damping is found to quickly redistribute the GAM energy in phase-space, due to the synergy of the finite orbit width of the passing ions and the cascade in wave number given by the phase mixing. When plasma parameters characteristic of realistic tokamak profiles are considered, the GAM decay time is found to be an order of magnitude lower than the decay due to the Landau damping alone, and in some cases of the same order of magnitude of the characteristic GAM drive time due to the nonlinear interaction with an ion-temperature-gradient (ITG) mode. In particular, the radial mode structure evolution in time is investigated here and reproduced quantitatively by means of a dedicated initial value code and diagnostics.
Water self-diffusivity confined in graphene nanogap using molecular dynamics simulations
Authors: Moulod M. , Hwang G.
Published: November 2016

Fundamental understanding of water confined in graphene is crucial to optimally design and operate sustainable energy, water desalination, and bio-medical systems. However, the current understanding predominantly remains in the static properties near the graphene surfaces. In this paper, a key water transport property, i.e., self-diffusivity, is examined under confinement by various graphene nanogap sizes (Lz = 0.7–4.17 nm), using molecular dynamics simulations with various graphene-water interatomic potentials (Simple Point Charge (SPC/E) and TIP3P water models). It is found that the water self-diffusivity nearly linearly decreases as the graphene-water interatomic potential energy increases at a given nanogap size. It also decreases as the graphene nanogap size decreases down to Lz = 1.34 nm; however, it shows the peak water self-diffusivity at Lz = 0.8 nm and then continues to decrease. The peak water self-diffusivity is related to the significant change of the overlapping surface force, and associated, nonlinear local water density distribution. The in-plane water self-diffusivity is higher up to nearly an order of magnitude than that of the out-of-plane due to the geometrical confinement effect by the graphene nanogap. The obtained results provide a roadmap to fundamentally understand the water transport properties in the graphene geometries and surface interactions.
Dynamics and transport properties of three surface quasigeostrophic point vortices
Authors: Taylor C. K. , Llewellyn Smith Stefan G.
Published: November 2016

The surface quasi-geostrophic (SQG) equations are a model for low-Rossby number geophysical flows in which the dynamics are governed by potential temperature dynamics on the boundary. We examine point vortex solutions to this model as well as the chaotic flows induced by three point vortices. The chaotic transport induced by these flows is investigated using techniques of Poincaré maps and the Finite Time Braiding Exponent (FTBE). This chaotic transport is representative of the mixing in the flow, and these terms are used interchangeably in this work. Compared with point vortices in two-dimensional flow, the SQG vortices are found to produce flows with higher FTBE, indicating more mixing. Select results are presented for analyzing mixing for arbitrary vortex strengths.
A study on Si/Al2O3 paramagnetic point defects
Authors: Kühnhold-Pospischil S. , Saint-Cast P. , Hofmann M. , Weber S. , Jakes P. , Eichel R.-A. , Granwehr J.
Published: November 2016

In this contribution, negative charges and electronic traps related to the Si/Al2O3 interface were measured and related to paramagnetic point defects and molecular vibrations. To this end, contactless capacitance voltage measurements, X-band electron paramagnetic resonance (EPR), and infrared spectroscopy were carried out, and their results were compared. A change in the negative charge density and electron trap density at the Si/Al2O3 interface was achieved by adding a thermally grown SiO2 layer with varying thicknesses and conducting an additional temperature treatment. Using EPR, five paramagnetic moments were detected in Si/(SiO2)/Al2O3 samples with g values of g1=2.0081±0.0002, g2=2.0054±0.0002, g3=2.0003±0.0002, g4=2.0026±0.0002, and g5=2.0029±0.0002. Variation of the Al2O3 layer thickness shows that paramagnetic species associated with g1, g2, and g3 are located at the Si/Al2O3 interface, and those with g4 and g5 are located within the bulk Al2O3. Furthermore, g1, g2, and g3 were shown to originate from oxygen plasma exposure during Al2O3 deposition. Comparing the g values and their location within the Si/Al2O3 system, g1 and g3 can be attributed to Pb0 centers, g3 to Si dangling bonds (Si-dbs), and g4 and g5 to rotating methyl radicals. All paramagnetic moments observed in this contribution disappear after a 5-min temperature treatment at 450 °C. The deposition of an additional thermal SiO2 layer between the Si and the Al2O3 decreases the negative fixed charge density and defect density by about one order of magnitude. In this contribution, these changes can be correlated with a decrease in amplitude of the Si-db signal. Pb0 and the methyl radical signals were less affected by this additional SiO2 layer. Based on these observations, microscopic models for the negative fixed charge density (Qtot) and the interface trap density (Dit) and the connection between these values are proposed.
A microfluidic method and custom model for continuous, non-intrusive biofilm viscosity measurements under different nutrient conditions
Authors: Greener J. , Parvinzadeh Gashti M. , Eslami A. , Zarabadi M. P. , Taghavi S. M.
Published: November 2016

Straight, low-aspect ratio micro flow cells are used to support biofilm attachment and preferential accumulation at the short side-wall, which progressively reduces the effective channel width. The biofilm shifts downstream at measurable velocities under the imposed force from the constant laminar co-flowing nutrient stream. The dynamic behaviour of the biofilm viscosity is modeled semi-analytically, based on experimental measurements of biofilm dimensions and velocity as inputs. The technique advances the study of biofilm mechanical properties by strongly limiting biases related to non-Newtonian biofilm properties (e.g., shear dependent viscosity) with excellent time resolution. To demonstrate the proof of principle, young Pseudomonas sp. biofilms were analyzed under different nutrient concentrations and constant micro-flow conditions. The striking results show that large initial differences in biofilm viscosities grown under different nutrient concentrations become nearly identical in less than one day, followed by a continuous thickening process. The technique verifies that in 50 h from inoculation to early maturation stages, biofilm viscosity could grow by over 2 orders of magnitude. The approach opens the way for detailed studies of mechanical properties under a wide variety of physiochemical conditions, such as ionic strength, temperature, and shear stress.
Electrospinning jet behaviors under the constraints of a sheath gas
Authors: Zhao Yang , Jiang Jiaxin , Li Wenwang , Wang Xiang , Zhang Kai , Zhu Ping , Zheng Gaofeng
Published: November 2016

Increasing the ejection efficiency and uniformity of nanofibers is the key to applications of electrospinning technology. In this work, a novel electrospinning spinneret with a sheath gas passageway is designed. The frictional resistance that stems from the sheath gas provides additional stretching and restriction forces on the jet. The sheath gas also reduces interference and enhances the stability of the charged jet. A bead-on-strain simulation model is built up to determine the constraint effects of the sheath gas. Simulation results show that the sheath gas decreases the motion area and increases the stretching ratio of the liquid jet. The stretching force from the sheath gas decreases the diameter and increases the uniformity of the nanofiber. As the gas pressure increases from 0 kPa to 50 kPa, the critical voltage of the jet ejection decreases from 8.4 kV to 2.5 kV, the diameter of the nanofiber deposition zone decreases from 40 cm to 10 cm, and the diameter of the nanofibers decreases from 557.97 nm to 277.73 nm. The uniformity of nanofibers can be improved significantly using a sheath gas. The sheath gas contributes to the rapid deposition of a uniform nanofibrous membrane and the industrial applications of electrospinning.