bluuebunny/crossref_metadata_2025 huggingface dataset:
EGFR confers radioresistance in human oropharyngeal carcinoma by activating endoplasmic reticulum stress signaling PERK‐eIF2α‐GRP94 and IRE1α‐XBP1‐GRP78
Authors: Zhang Miao , Han Ning , Jiang Yuanjun , Wang Jie , Li Gaiyan , Lv Xintong , Li Guang , Qiao Qiao
Published: November 2018

The activation of epidermal growth factor receptor (EGFR) is associated with radioresistance in malignant tumors. Specifically, radiation can destroy endoplasmic reticulum (ER) homeostasis to induce ER stress (ERS). However, the effect of EGFR‐mediated regulation of ERS signaling pathway on radiosensitivity has not yet been reported. The present study showed that silencing EGFR increased radiosensitivity of both radiosensitive and radioresistant oropharyngeal squamous cell carcinoma (OSCC) cells by inhibiting ER stress signaling (PERK‐eIF2α‐GRP94 and IRE1α‐XBP1‐GRP78). This effect was abolished by pretreatment with EGF, however. In addition, knockdown of EGFR in OSCC cells inhibited DNA double‐stand break repair and autophagy while increased radiation‐induced apoptosis. Conversely, activating ERS inhibited the aforementioned functions. Furthermore, EGF increased ER stress‐independent ERK and AKT signaling upon irradiation of OSCC cells. Immunohistochemical analysis of 80 tissue samples from OSCC patients showed that co‐expression of EGFR and PERK was associated with poor prognosis. It thus appears EGFR confers radioresistance in OSCC by activating ER stress signaling. These results suggested that the cooperative effects of radiotherapy and EGFR‐targeted inhibitor therapy can be further improved by inhibiting PERK‐eIF2α‐GRP94 and IRE1α‐GRP78 in non‐response oropharyngeal carcinoma patients.
Construction of 3DOM Carbon Nitrides with Quasi‐Honeycomb Structures for Efficient Photocatalytic H2 Production
Authors: Cao Ruya , Yang Hongcen , Deng Xiaolong , Sun Pengxiao , Zhang Shouwei , Xu Xijin
Published: November 2018

Constructing porous nanostructures is an effective strategy for improving photocatalytic activity and separating charge carriers in the visible area. In this paper, the macroporous g‐C3N4 photocatalyst with a quasi‐honeycomb structure was successfully built with a simple thermal condensation‐colloidal template way for photocatalytic hydrogen production. The microstructure, electron transfer and optical absorption capability of quasi‐honeycomb g‐C3N4 have been methodically investigated. The obvious structural susceptibility to light catching, and charge carriers separation and transfer were realized. These results illustrated that compared with bulk g‐C3N4, the optimized g‐C3N4 photocatalyst with a quasi‐honeycomb structure had the higher H2 release rate of 395 μmol h−1, the corresponding apparent quantum efficiency (AQE) of 6.27 %, and excellent cycle stability. This work demonstrates that the quasi‐honeycomb structures can be designed and used to synthesize highly‐efficient g‐C3N4 nanoarchitectures, providing a reference for enhancing photocatalytic H2 evolution performance.
Spiropyran‐Based Nanocarrier: A New Zn2+‐Responsive Delivery System with Real‐Time Intracellular Sensing Capabilities
Authors: Heng Sabrina , Zhang Xiaozhou , Pei Jinxin , Adwal Alaknanda , Reineck Philipp , Gibson Brant C. , Hutchinson Mark R. , Abell Andrew D.
Published: November 2018

A new spiropyran‐based stimuli‐responsive delivery system is fabricated. It encapsulates and then releases an extraneous compound in response to elevated levels of Zn2+, a critical factor in cell apoptosis. A C12‐alkyl substituent on the spiropyran promotes self‐assembly into a micelle‐like nanocarrier in aqueous media, with nanoprecipitation and encapsulation of added payload. Zn2+ binding occurs to an appended bis(2‐pyridylmethyl)amine group at biologically relevant micromolar concentration. This leads to switching of the spiropyran (SP) isomer to the strongly fluorescent ring opened merocyanine‐Zn2+ (MC‐Zn2+) complex, with associated expansion of the nanocarriers to release the encapsulated payload. Payload release is demonstrated in solution and in HEK293 cells by encapsulation of a blue fluorophore, 7‐hydroxycoumarin, and monitoring its release using fluorescence spectroscopy and microscopy. Furthermore, the use of the nanocarriers to deliver a caspase inhibitor, Azure B, into apoptotic cells in response to an elevated Zn2+ concentration is demonstrated. This then inhibits intracellular caspase activity, as evidenced by confocal microscopy and in real‐time by time‐lapsed microscopy. Finally, the nanocarriers are shown to release an encapsulated proteasome inhibitor (5) in Zn2+‐treated breast carcinoma cell line models. This then inhibits intracellular proteasome and induces cytotoxicity to the carcinoma cells.
Visible‐Light Photocatalysis of the Ketyl Radical Coupling Reaction
Authors: Xia Qing , Dong Jianyang , Song Hongjian , Wang Qingmin
Published: November 2018

Ketyl radical coupling reactions for the construction of diversely functionalized alcohols have been continuously developed for many decades. Based on the recently widespread application of photocatalysis, ketyl radical coupling reactions have also witnessed rapid development. This Minireview aims to briefly and concisely summarize the methods to construct ketyl radical intermediates through visible‐light photocatalysis over the past 10 years. The ketyl‐radical‐generation activators are grouped as Lewis acids, Brønsted acids, in situ generated Brønsted acids, and others.
Regulating a key mitotic regulator, polo‐like kinase 1 (PLK1)
Authors: Colicino Erica G. , Hehnly Heidi
Published: November 2018

During cell division, duplicated genetic material is separated into two distinct daughter cells. This process is essential for initial tissue formation during development and to maintain tissue integrity throughout an organism's lifetime. To ensure the efficacy and efficiency of this process, the cell employs a variety of regulatory and signaling proteins that function as mitotic regulators and checkpoint proteins. One vital mitotic regulator is polo‐like kinase 1 (PLK1), a highly conserved member of the polo‐like kinase family. Unique from its paralogues, it functions specifically during mitosis as a regulator of cell division. PLK1 is spatially and temporally enriched at three distinct subcellular locales; the mitotic centrosomes, kinetochores, and the cytokinetic midbody. These localization patterns allow PLK1 to phosphorylate specific downstream targets to regulate mitosis. In this review, we will explore how polo‐like kinases were originally discovered and diverged into the five paralogues (PLK1‐5) in mammals. We will then focus specifically on the most conserved, PLK1, where we will discuss what is known about how its activity is modulated, its role during the cell cycle, and new, innovative tools that have been developed to examine its function and interactions in cells.
Topologies of Nodal Sets of Random Band‐Limited Functions
Authors: Sarnak Peter , Wigman Igor
Published: November 2018

It is shown that the topologies and nestings of the zero and nodal sets of random (Gaussian) band‐limited functions have universal laws of distribution. Qualitative features of the supports of these distributions are determined. In particular, the results apply to random monochromatic waves and to random real algebraic hypersurfaces in projective space. © 2018 Wiley Periodicals, Inc.
Visualizing Secretory Cargo Transport in Budding Yeast
Authors: Casler Jason C. , Glick Benjamin S.
Published: November 2018

Budding yeast is an excellent model organism for studying the dynamics of the Golgi apparatus. To characterize Golgi function, it is important to visualize secretory cargo as it traverses the secretory pathway. We describe a recently developed approach that generates fluorescent protein aggregates in the lumen of the yeast endoplasmic reticulum and allows the fluorescent cargo to be solubilized for transport through the Golgi by addition of a small‐molecule ligand. We further describe how to generate a yeast strain expressing the regulatable secretory cargo, and we provide protocols for visualizing the cargo by 4D confocal microscopy and immunoblotting. © 2018 by John Wiley & Sons, Inc.
Synthesis of g‐C3N4 Nanosheets by Using a Highly Condensed Lamellar Crystalline Melamine–Cyanuric Acid Supramolecular Complex for Enhanced Solar Hydrogen Generation
Authors: Vu Nhu‐Nang , Nguyen Chinh‐Chien , Kaliaguine Serge , Do Trong‐On
Published: November 2018

A highly condensed lamellar melamine–cyanuric acid supramolecular (MCS) complex was synthesized in an autoclave at high pressure as a precursor for preparing g‐C3N4 nanosheets. Given the distinctive properties of the prepared MCS complex, an efficient g‐C3N4 nanosheet photocatalyst can be obtained by heat treatment of this MCS complex under Ar followed by calcination in air at 400 °C. The resulting nanosheets with in‐plane nanoholes showed an extremely high specific surface area (≈270 m2 g−1) and significantly enhanced light absorption in the visible region. This phenomenon is observed for the first time in carbon nitride nanosheets. The enhanced light absorption results from the sizeable conjugated system of tri‐striazine units in the carbon nitride framework, coupled with the structural defects arising from the presence of oxygen‐containing groups induced during the synthesis. Consequently, the obtained carbon nitride nanosheets exhibited excellent performance for hydrogen generation under sunlight and especially under visible light. Its quantum efficiency (QE) of 20.9 % at 420 nm is one of the highest reported values for carbon nitride materials. A QE of 3.5 % could be observed even at 590 nm. The integrated QE of this material in the visible region (420–600 nm) is approximately 1 %. To the best of our knowledge this is the highest value compared to all other the carbon nitride nanosheet materials reported previously.
Preparation, optimization, and pharmacokinetic study of nanoliposomes loaded with triacylglycerol‐bound punicic acid for increased antihepatotoxic activity
Authors: Adu‐Frimpong Michael , Firempong Caleb Kesse , Omari‐Siaw Emmanuel , Wang Qilong , Mukhtar Yusif Mohammed , Deng Wenwen , Yu Qingtong , Xu Ximing , Yu Jiangnan
Published: November 2018

Punicic acid of pomegranate oil (PAP) has gained heightened interest due to several health benefits, such as anticarcinogenic, antidiabetic, and antiatherosclerotic properties. However, these bioactivities have been hampered by chemical instability, poor water solubility, rapid metabolism, and low bioavailability of PAP. Therefore, this study was aimed at optimizing the liposomal formulation of Triacylglycerol‐bound punicic acid with its regioisomers (TPAR) for improved oral bioavailability and increased hepatoprotection through antioxidation and anti‐inflammation. Herein, the optimized TPAR nanoliposome (TPAR‐NL) was developed using thin‐film dispersion method and subsequently characterized with appropriate indices. The optimized TPAR‐NL produced fairly stable spherical nanoparticles (˂ 200 nm) with encapsulation efficiency (%EE) of 85.77%, as well as enhanced in vitro release and improved oral bioavailability. The TPAR‐NL exhibited profound antihepatotoxic effect in mice pretreated with carbon tetrachloride (CCl4) via reduction of serum alanine aminotransferase, aspartate aminotransferase, and total bilirubin levels compared with free TPAR. The TPAR‐loaded liposome also significantly reduced oxidative stress by increasing superoxide dismutase and glutathione levels while lowering malonaldehyde concentration compared with the free TPAR. The TPAR‐LNF further exhibited remarkable anti‐inflammatory activity compared with the free drug via inhibition of interleukin‐6 and tumor necrosis factor‐alpha generation. Thus, the developed nanoliposomes potentiated the antihepatotoxic activity of TPAR via antioxidation and anti‐inflammation.
A Danish register‐based study on involuntary treatment in anorexia nervosa
Authors: Clausen L. , Larsen J. T. , Bulik C. M. , Petersen L.
Published: November 2018

Objective

Involuntary treatment is controversial and widely debated, but remains a significant component of treatment for severe anorexia nervosa. Given how little is known about this topic, we describe the frequency of various involuntary measures in a national cohort of all patients diagnosed with anorexia nervosa. In a subsample of patients, we explored predictors of the first involuntary measure recorded.

Method

Descriptive statistics and Cox proportional hazard analyses were conducted using the national registers of Denmark covering the total population. Data from the National Patient Register and the Psychiatric Central Research Register including all psychiatric visits from 1969 onwards were merged with data from the National Register on Coercion covering 1999 onward. Involuntary measures registered between 2000 and 2013 were analyzed.

Results

A total of 4,727 patients with a diagnosis of anorexia nervosa representing 16,592 admissions were included. Eighteen percent experienced at least one involuntary measure. A variety of measures were used with tube feeding being the most frequent followed by mechanical restraint, involuntary medication, physical restraint, constant observation, and sedative medication. A subsample of 2% of AN patients had more than 100 involuntary measures recorded. The first recorded involuntary measure was predicted by most but not all psychiatric comorbidities, especially schizophrenia, autism spectrum, and personality disorders, older age at first diagnosis, and previous admissions.

Discussion

It is important to develop a more granular understanding of patients at risk of requiring involuntary treatment and to determine how best to treat them effectively with minimal use of involuntary measures.
Demographic trends and KRAS/BRAFV600E mutations in colorectal cancer patients of South China: A single‐site report
Authors: Fu Xinhui , Huang Yan , Fan Xinjuan , Deng Yanhong , Liu Huanliang , Zou Hongzhi , Wu Peihuang , Chen Zhiting , Huang Jinglin , Wang Jingxuan , Lin Hanjie , Huang Shuhui , Tan Xiaoli , Lan Ping , Wang Lei , Wang Jian‐ping
Published: November 2018

The incidence of colorectal cancer (CRC) is increasing in China. Here, we aimed to evaluate the latest demographic trends and KRAS/BRAF mutations status of Chinese CRC. Five thousand five hundred and forty‐six CRC patients diagnosed from 2010 to 2017 were involved. KRAS exon 2 and BRAFV600E mutations were detected by Sanger sequencing and high‐resolution melting analysis or allelic‐specific probe method. Gene mutation profiles and clinicopathologic characteristics of 5495 patients were analyzed. The joinpoint regression model was used to predict the demographic data in 2018. We found KRAS exon 2 and BRAFV600E mutation rates were 37.7 and 2.8% in CRC patients. Tumors with KRAS exon 2 mutations were more likely to be present in female and patients aged older than 75 years, right colon and have well‐differentiated histology. Tumors with BRAFV600E mutations were more likely to be present in the female, right colon and have poorly differentiated histology. From 2010 to 2017, the percentage of colon cancer and tubular adenocarcinoma in CRC increased substantially (from 39.3 to 51.8%, from 78.6 to 93.4%, respectively). The percentage of right colon cancer increased from 18.3 to 20.5%, which predictively may keep at 22.6% in 2018. The rise trends for patients with moderate differentiation tumor or KRAS exon 2 mutated tumor were apparent (from 50.3 to 78.6%, from 32.8 to 39.7%, respectively). In conclusion, in recent 8 years, there is a shift to the colon, especially right colon in the incidence of Chinese CRC. Moreover tubular adenocarcinoma is becoming the primary histology type.
Glioblastoma endothelium drives bevacizumab‐induced infiltrative growth via modulation of PLXDC1
Authors: Falchetti Maria Laura , D'Alessandris Quintino Giorgio , Pacioni Simone , Buccarelli Mariachiara , Morgante Liliana , Giannetti Stefano , Lulli Valentina , Martini Maurizio , Larocca Luigi Maria , Vakana Eliza , Stancato Louis , Ricci‐Vitiani Lucia , Pallini Roberto
Published: November 2018

Bevacizumab, a VEGF‐targeting monoclonal antibody, may trigger an infiltrative growth pattern in glioblastoma. We investigated this pattern using both a human specimen and rat models. In the human specimen, a substantial fraction of infiltrating tumor cells were located along perivascular spaces in close relationship with endothelial cells. Brain xenografts of U87MG cells treated with bevacizumab were smaller than controls (p = 0.0055; Student t‐test), however, bands of tumor cells spread through the brain farther than controls (p < 0.001; Student t‐test). Infiltrating tumor Cells exhibited tropism for vascular structures and propensity to form tubules and niches with endothelial cells. Molecularly, bevacizumab triggered an epithelial to mesenchymal transition with over‐expression of the receptor Plexin Domain Containing 1 (PLXDC1). These results were validated using brain xenografts of patient‐derived glioma stem‐like cells. Enforced expression of PLXDC1 in U87MG cells promoted brain infiltration along perivascular spaces. Importantly, PLXDC1 inhibition prevented perivascular infiltration and significantly increased the survival of bevacizumab‐treated rats. Our study indicates that bevacizumab‐induced brain infiltration is driven by vascular endothelium and depends on PLXDC1 activation of tumor cells.
Multigene panel sequencing of established and candidate melanoma susceptibility genes in a large cohort of Dutch non‐CDKN2A/CDK4 melanoma families
Authors: Potjer Thomas P. , Bollen Sander , Grimbergen Anneliese J.E.M. , van Doorn Remco , Gruis Nelleke A. , van Asperen Christi J. , Hes Frederik J. , van der Stoep Nienke ,   on behalf of the Dutch Working Group for Clinical Oncogenetics
Published: November 2018

Germline mutations in the major melanoma susceptibility gene CDKN2A explain genetic predisposition in only 10–40% of melanoma‐prone families. In our study we comprehensively characterized 488 melanoma cases from 451 non‐CDKN2A/CDK4 families for mutations in 30 established and candidate melanoma susceptibility genes using a custom‐designed targeted gene panel approach. We identified (likely) pathogenic variants in established melanoma susceptibility genes in 18 families (n = 3 BAP1, n = 15 MITF p.E318K; diagnostic yield 4.0%). Among the three identified BAP1‐families, there were no reported diagnoses of uveal melanoma or malignant mesothelioma. We additionally identified two potentially deleterious missense variants in the telomere maintenance genes ACD and TERF2IP, but none in the POT1 gene. MC1R risk variants were strongly enriched in our familial melanoma cohort compared to healthy controls (R variants: OR 3.67, 95% CI 2.88–4.68, p <0.001). Several variants of interest were also identified in candidate melanoma susceptibility genes, in particular rare (pathogenic) variants in the albinism gene OCA2 were repeatedly found. We conclude that multigene panel testing for familial melanoma is appropriate considering the additional 4% diagnostic yield in non‐CDKN2A/CDK4 families. Our study shows that BAP1 and MITF are important genes to be included in such a diagnostic test.
Quantitative FRET measurement based on spectral unmixing of donor, acceptor and spontaneous excitation‐emission spectra
Authors: Su Wenhua , Du Mengyan , Lin Fangrui , Zhang Chenshuang , Chen Tongsheng
Published: November 2018

The spontaneous excitation‐emission (ExEm) spectrum is introduced to the quantitative mExEm‐spFRET methodology we recently developed as a spectral unmixing component for quantitative fluorescence resonance energy transfer measurement, named as SPEES‐FRET method. The spectral fingerprints of both donor and acceptor were measured in HepG2 cells with low autofluorescence separately expressing donor and acceptor, and the spontaneous spectral fingerprint of HEK293 cells with strong autofluoresence was measured from blank cells. SPEES‐FRET was performed on improved spectrometer‐microscope system to measure the FRET efficiency (E) and concentration ratio (R
C) of acceptor to donor vales of FRET tandem plasmids in HEK293 cells, and obtained stable and consistent results with the expected values. Moreover, SPEES‐FRET always obtained stable results for the bright and dim cells coexpressing Cerulean and Venus or Cyan Fluorescent Protein (CFP)‐Bax and Yellow fluorescent protein (YFP)‐Bax, and the E values between CFP‐Bax and YFP‐Bax were 0.02 for healthy cells and 0.14 for the staurosporine (STS)‐treated apoptotic cells. Collectively, SPEES‐FRET has very strong robustness against cellular autofluorescence, and thus is applicable to quantitative evaluation on the protein‐protein interaction in living cells with strong autofluoresence.
The whither of bacteriophytochrome‐based near‐infrared fluorescent proteins: Insights from two‐photon absorption spectroscopy
Authors: Lanin Aleksandr A. , Chebotarev Artem S. , Barykina Natalia V. , Subach Fedor V. , Zheltikov Aleksei M.
Published: November 2018

We present one‐ and two‐photon‐absorption fluorescence spectroscopic analysis of biliverdin (BV) chromophore–based single‐domain near‐infrared fluorescent proteins (iRFPs). The results of these studies are used to estimate the internal electric fields acting on BV inside iRFPs and quantify the electric dipole properties of this chromophore, defining the red shift of excitation and emission spectra of BV‐based iRFPs. The iRFP studied in this work is shown to fit well the global diagram of the red‐shift tunability of currently available BV‐based iRFPs as dictated by the quadratic Stark effect, suggesting the existence of the lower bound for the strongest red shifts attainable within this family of fluorescent proteins. The absolute value of the two‐photon absorption (TPA) cross section of a fluorescent calcium sensor based on the studied iRFP is found to be significantly larger than the TPA cross sections of other widely used genetically encodable fluorescent calcium sensors.
A case review of a patient experience of photopheresis using a peripherally inserted central catheter
Authors: Rushton Cherie , Jackson Andrew , Goddard Kathryn , Alfred Arun
Published: November 2018

Extracorporeal photopheresis (ECP) is a cell based immunomodulatory therapy in which the patient is attached intravenously to a cell separating machine. During ECP a patient's blood is collected via either a central venous access device (CVAD) or a peripherally inserted 16G arterial venous fistula needle in either one or both antecubital fossa. However, patients presenting for ECP with GVHD repeatedly present a challenge to the ECP team due to poor venous access resulting from previous therapies and skin changes. The use of peripherally inserted central venous catheters (PICCs) offers an alternative route of vascular access for this cohort of patients. Here we present a case report of a patient successfully treated with ECP following the insertion of a PICC line.
Constraint structure optimization to a specific minimum using ionization energy
Authors: Harada Iori , Nakayama Akira , Hasegawa Jun‐ya
Published: November 2018

A structure optimization method with ionization energy constraint is developed to explore structures with specific ionization energy. The Levine‐Coe‐Martínez penalty function (J Phys Chem B 2008, 112, 405) was adopted, and the penalty function includes a predefined core‐ionization energy and inner‐shell ionization energy. For an SN2 reaction, isomerization of a platinum complex, a proton transfer reaction, and carbon monoxide adsorption on a palladium cluster, the present method was tested, and the targeted energy minima were obtained as designated by the input ionization energy. The shape of the objective function, the parameters in the penalty function, and structural changes during the optimization process were discussed. An automated parameter setting and possible problems are discussed for future direction. © 2018 Wiley Periodicals, Inc.
Interleukin‐37 inhibits osteoclastogenesis and alleviates inflammatory bone destruction
Authors: Tang Ruohui , Yi Jin , Yang Jing , Chen Yueqi , Luo Wei , Dong Shiwu , Fei Jun
Published: November 2018

Excessive osteoclast formation is one of the important pathological features of inflammatory bone destruction. Interleukin‐37 (IL‐37) is an anti‐inflammatory agent that is present throughout the body, but it displays low physiological retention. In our study, high levels of the IL‐37 protein were detected in clinical specimens from patients with bone infections. However, the impact of IL‐37 on osteoclast formation remains unclear. Next, IL‐37 alleviated the inflammatory bone destruction in the mouse in vivo. We used receptor activator of nuclear factor‐κB ligand and lipopolysaccharide to trigger osteoclastogenesis under physiological and pathological conditions to observe the role of IL‐37 in this process and explore the potential mechanism of this phenomenon. In both induction models, IL‐37 exerted inhibitory effects on osteoclast differentiation and bone resorption. Furthermore, IL‐37 decreased the phosphorylation of inhibitor of κBα and p65 and the expression of nuclear factor of activated T cells c1, while the dimerization inhibitor of myeloid differentiation factor 88 reversed the effects. These data provide evidence that IL‐37 modulates osteoclastogenesis and a theoretical basis for the clinical application of IL‐37 as a treatment for bone loss–related diseases.
Reaching the bottom of the pyramid with a social enterprise model: The case of the NGO Entrepreneurs du Monde and its social enterprise Nafa Naana in Burkina Faso
Authors: Dumalanède Constance , Payaud Marielle A.
Published: November 2018

An analysis of how Entrepreneurs du Monde, a nongovernmental organization, transformed its operations in Burkina Faso into a social enterprise highlights the actions that organizations can take to improve the sustainability, as well as the social and economic value, of their operations in bottom‐of‐the‐pyramid markets. Using the business model canvas, the study shows how the business model of the Save for a Stove development program changed as it became Nafa Naana, an independent social enterprise that shifted an original focus on social goals toward a dual focus on social and economic objectives. In effect, Entrepreneur du Monde acted as an incubator for Nafa Naana, allowing it to develop its key competencies through its partnerships with local suppliers, producers, and distributors, and to access the knowledge and financial resources needed to ensure its sustainability in the long term.
The role of social networks in entrepreneurial ecosystems: The case of #StartupLokal in Jakarta
Authors: Wahyuningtyas Sih Yuliana , Hanoteau Julien , Vial Virginie
Published: November 2018

With the largest economy in Southeast Asia and the fourth‐largest population in the world, Indonesia has tremendous entrepreneurial potential. The recent fast development of Internet‐based businesses there brings opportunities for startups to flourish. Some have already achieved remarkable success, despite a lack of institutional support to provide the necessary networks, material resources, and other elements of an entrepreneurial culture. Increasingly, these factors for success are being provided by entrepreneurial ecosystems in which entrepreneurial networks play a major role. The experiences of #StartupLokal illustrate how an entrepreneurial network can sprout from the field, relying on the passion and drive of successful serial entrepreneurs. They also reveal how the entrepreneurial community can inspire potential and new startup leaders, strengthen the entrepreneurial culture, and facilitate access to resources.
Growing global in the sharing economy: Lessons from Uber and Airbnb
Authors: Anwar Syed Tariq
Published: November 2018

A study of the globally oriented expansion strategies of Uber and Airbnb offer business leaders insight into dealing with the ups and downs of the sharing economy. Although both firms have suffered operational and managerial setbacks and face logistical and regulatory hurdles, they continue to enjoy remarkable international growth. Thanks to their entrepreneurial initiatives, application of digital models, savvy branding, and customer‐centric focus, Uber and Airbnb remain staunchly competitive in each of their demanding sectors. Their experiences highlight the value of efficient business models, niche strategies, and connectivity.
Standardized Nutrition Protocol for Very Low‐Birth‐Weight Infants Resulted in Less Use of Parenteral Nutrition and Associated Complications, Better Growth, and Lower Rates of Necrotizing Enterocolitis
Authors: Barr Priscilla A. , Mally Pradeep V. , Caprio Martha C.
Published: November 2018

Background

We assessed the impact of a standardized nutrition initiative for very low‐birth‐weight (VLBW) infants on their nutrition and clinical outcomes.

Methods

This was a prospective analysis of VLBW infants born before and after the initiation of a nutrition protocol. This protocol included trophic feeds, feeding advancement, fortification guidelines, parameters on the concentration of parenteral nutrition (PN), and the discontinuation of PN and central lines. Gastric residual monitoring was discontinued. Statistical analyses were performed with Fisher's exact and Student's t‐tests. Primary outcome measures were days receiving PN, days made nil per os (NPO) after feeding initiation, necrotizing enterocolitis, and growth parameters. Secondary outcome measures were central‐line days, sepsis, blood transfusions, cholestasis, osteopenia, chronic lung disease, and retinopathy of prematurity.

Results

136 VLBW infants were analyzed, including 77 in the preprotocol group and 59 in the postprotocol group. Infants postprotocol were found to have reduced PN days (26.1 versus [vs] 18.4, P < .01), fewer days made NPO after feeding initiation (7.2 vs 4.0, P = .02), NEC (7.8% vs 0%, P = 0.038), central‐line days (26.5 vs 18.6, P < .01), cholestasis (16% vs 3%, P = .02), and blood transfusions (5.3 vs 3.1, P = .028). Growth, defined by change in z‐score from birth to discharge, improved for weight (−1.3 vs −0.8, P < .01), length (−1.5 vs −1.0, P = .033), and head (−1.1 vs −0.6, P = .024).

Conclusion

Initiation of a standardized nutrition initiative for VLBW infants significantly improved growth, reduced PN use, and improved patient outcomes.
Discovery of cancer cell proliferation inhibitors from Salviae miltiorrhizae radix et rhizoma by a trace peak enrichment approach
Authors: Zhang Xiao‐wei , Yang Lin , An Lin , Li Ping , Chen Jun
Published: November 2018

Salviae miltiorrhizae radix et rhizoma is a traditional herbal medicine with anti‐cancer activities. In this work, a trace peak enrichment approach combined with a cell proliferation assay was applied for screening cancer cell proliferation inhibitors from the extract of S. miltiorrhiza. A set of 123 peak fractions were prepared, and by comprehensive screening, 21 tanshinones were screened out as cancer cell proliferation inhibitors and their structures were tentatively identified by liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry analysis. The inhibitory activities of nine available screened tanshinones were validated, with their IC50 values ranging from 0.63 to 28.40 μM, indicating their activities strongly inhibit the proliferation of cancer cells. This study presents tanshinones that are potential cancer cell proliferation inhibitors and may explain the anti‐cancer activity of S. miltiorrhiza.
A novel calibration method incorporating nonlinear optimization and ball‐bearing markers for cone‐beam CT with a parameterized trajectory
Authors: Li Guang , Luo Shouhua , You Chenyu , Getzin Matthew , Zheng Liang , Wang Ge , Gu Ning
Published: November 2018

Purpose

Cone‐beam (CB) CT is a powerful noninvasive imaging modality, and is widely used in many applications. Accurate geometric parameters are essential for high‐quality image reconstruction. Usually, a CBCT system with higher spatial resolution, particularly on the order of microns or nanometers, will be more sensitive to the parametric accuracy. Here, we propose a novel calibration method combining a simple phantom containing ball bearing markers and an advanced optimization procedure. This method can be applied to CBCT with reproducible geometry and frame‐to‐frame invariant geometric parameters.

Methods

Our proposed simplex‐simulated annealing procedure minimizes the cost function that associates the geometrical parameters with the degree to which the back projections of the ball bearings in projections from various viewing angles converge, and the global minimum of the cost function corresponds to the actual geometric parameters. Specifically, six geometric parameters can be directly obtained by minimizing the cost function, and the last parameter, the distance from source to rotation axis (SRD), can be obtained using prior knowledge of the phantom — the spacing between the two ball bearings.

Results

Numerical simulation was performed to validate that the proposed method with various noise levels. With the proposed method, the mean errors and standard deviations can be reduced to ∼10% and less than 1/3 of a competing benchmark method in the case of strong Gaussian noise (sigma = 200% of the pixel size) and large tilt angle (tilt angle = ). The calibration experiments with micro‐CT and high‐resolution CT scanners demonstrate that the proposed method recovers imaging parameters accurately, leading to superior image quality.

Conclusion

The proposed method can obtain accurate geometric parameters of a CBCT system with a circular trajectory. While in the case of micro‐CT the proposed method has a performance comparable to the competing method, for high‐resolution CT, which is more sensitive to geometric calibration, the proposed method demonstrates higher calibration accuracy and more robustness than the benchmark algorithm.
MRI‐guided transurethral insonation of silica‐shell phase‐shift emulsions in the prostate with an advanced navigation platform
Authors: Anthony Gregory J. , Bader Kenneth B. , Wang James , Zamora Marta , Ostdiek Allison , Antic Tatjana , Krueger Sascha , Weiss Steffen , Trogler William C. , Blair Sarah L. , Kummel Andrew C. , Sammet Steffen
Published: November 2018

Purpose

In this study, the efficacy of transurethral prostate ablation in the presence of silica‐shell ultrasound‐triggered phase‐shift emulsions (sUPEs) doped with MR contrast was evaluated. The influence of sUPEs on MR imaging assessment of the ablation zone was also investigated.

Methods

sUPEs were doped with a magnetic resonance (MR) contrast agent, Gd2O3, to assess ultrasound transition. Injections of saline (sham), saline and sUPEs alone, and saline and sUPEs with Optison microbubbles were performed under guidance of a prototype interventional MRI navigation platform in a healthy canine prostate. Treatment arms were evaluated for differences in lesion size, T1 contrast, and temperature. In addition, non‐perfused areas (NPAs) on dynamic contrast‐enhanced (DCE) MRI, 55°C isotherms, and areas of 240 cumulative equivalent minutes at 43°C (CEM43) dose or greater computed from MR thermometry were measured and correlated with ablated areas indicated by histology.

Results

For treatment arms including sUPEs, the computed correlation coefficients between the histological ablation zone and the NPA, 55°C isotherm, and 240 CEM43 area ranged from 0.96–0.99, 0.98–0.99, and 0.91–0.99, respectively. In the absence of sUPEs, the computed correlation coefficients between the histological ablation zone and the NPA, 55°C isotherm, and 240 CEM43 area were 0.69, 0.54, and 0.50, respectively. Across all treatment arms, the areas of thermal tissue damage and NPAs were not significantly different (P = 0.47). Areas denoted by 55°C isotherms and 240 CEM43 dose boundaries were significantly larger than the areas of thermal damage, again for all treatment arms (P = 0.009 and 0.003, respectively). No significant differences in lesion size, T1 contrast, or temperature were observed between any of the treatment arms (P > 0.0167). Lesions exhibiting thermal fixation on histological analysis were present in six of nine insonations involving sUPE injections and one of five insonations involving saline sham injections. Significantly larger areas (P = 0.002), higher temperatures (P = 0.004), and more frequent ring patterns of restricted diffusion on ex vivo diffusion‐weighted imaging (P = 0.005) were apparent in lesions with thermal fixation.

Conclusions

T1 contrast suggesting sUPE transition was not evident in sUPE treatment arms. The use of MR imaging metrics to predict prostate ablation was not diminished by the presence of sUPEs. Lesions generated in the presence of sUPEs exhibited more frequent thermal fixation, though there were no significant changes in the ablation areas when comparing arms with and without sUPEs. Thermal fixation corresponded to some qualitative imaging features.
The influence of nuclear interactions on ionization chamber perturbation factors in proton beams: FLUKA simulations supported by a Fano test
Authors: Lourenço Ana , Bouchard Hugo , Galer Sebastian , Royle Gary , Palmans Hugo
Published: November 2018

Purpose

In all recent protocols for the reference dosimetry of clinical proton beams, ionization chamber perturbation factors are assumed to be unity. In this work, such factors were computed using the FLUKA Monte Carlo code for three ionization chamber types, with particular attention to the influence of nuclear interactions.

Methods

The accuracy of the transport algorithms implemented in FLUKA was first evaluated by performing a Fano cavity test. Ionization chamber perturbation factors were computed for the PTW‐34001 Roos® and the PTW‐34070 and PTW‐34073 Bragg peak® chambers for proton beams of 60–250 MeV using the same transport parameters that were needed to pass the Fano test.

Results

FLUKA was found to pass the Fano test within 0.15%. Ionization chamber simulation results show that the presence of the air cavity and the wall results in dose perturbations of the order of 0.6% and 0.8%, respectively. The perturbation factors are shown to be energy dependent and nuclear interactions must be taken into account for accurate calculation of the ionization chamber's response.

Conclusion

Ionization chamber perturbations can amount to 1% in high‐energy proton beams and therefore need to be considered in dosimetry procedures.
Analytical and experimental investigation of high velocity impact on foam core sandwich panel
Authors: Ahmadi Hamed , Liaghat Gholamhossein
Published: November 2018

In this article, a new analytical model is presented to simulate the behavior of a composite sandwich panel against the ballistic impact of a blunt head projectile. The analytical model proposes a multi‐stage perforation process based on experimental observations. Each stage is simulated by an individual mass‐spring model and the projectile's equation of motion is derived. In every step of the theoretical model, the energy balancing between the kinetic energy of the projectile and the energy absorbed by the target is considered. Significant energy‐absorbing mechanisms which accounted in the model are plugging of the front skin, delamination of composite laminates of the skins, debonding between skins and core, local core crushing ahead of projectile and partial penetration, core fracture and fiber fracture of the rear skin. Also, some strain energy is absorbed because of the global deformation of the target. Since the foam core failure consists of crushing and fracture, this model can calculate the residual velocity in every situation whether the foam is stiff and hard to crush or soft and crushable. In addition to the theoretical analysis, some experiments are carried out to validate the analytical predictions. A good agreement is confirmed between analytical and experimental results. POLYM. COMPOS., 40:2258–2272, 2019. © 2018 Society of Plastics Engineers
Mechanical Performance of Bio‐Waste‐Filled Carbon Fabric/Epoxy Composites
Authors: Nam Gibeop , Kim Jeachul , Song Jung‐Il
Published: November 2018

The aim of this study is to incorporate bio‐waste fillers that is, micro rice husk powder (RHP) and rice husk ash powder (RHA), into epoxy resins using a three‐roll mill and fabricate composites by reinforcing carbon fabrics via vacuum‐assisted resin transfer molding process and study their mechanical properties. The RHP and RHA fillers were prepared in the size range 2–6 μm by mechano‐ball milling and low‐temperature burning and only mechano‐ball milling, respectively. The effect of various wt% (0.3, 0.5, and 1) of the fillers was investigated in terms of the mechanical properties based on tensile, bending, and tension–tension fatigue tests. The mechanical results revealed optimum strengths, especially flexural (770 MPa, 0.3% RHP) and fatigue (five times fatigue life, 0.5% RHA) properties, due to the powder increasing the adhesive strength between the fiber and matrix and making crazes for arresting the development of cracks; these were further supported by the micro‐observations made using a scanning electron microscope. Overall, this study addresses environmental pollution by utilizing bio‐waste materials in carbon‐reinforced polymer composites with decent properties. POLYM. COMPOS., 40:E1504–E1511, 2019. © 2018 Society of Plastics Engineers
Fabrication and characterization of polyetherimide/polyvinyl acetate polymer blend membranes for CO2/CH4 separation
Authors: Abdul Mannan Hafiz , Yih Tan Ming , Nasir Rizwan , Muhktar Hilmi , Mohshim Dzeti Farhah
Published: November 2018

This article presents fabrication, characterization, and performance evaluation of polyetherimide (PEI)/polyvinyl acetate (PVAc) blend membranes. Polymer blend membranes with various blend ratios of PEI/PVAc were prepared by solution casting and evaporation technique. Morphology and miscibility of polymer blend membranes were characterized by field emission scanning electron microscope (FESEM) and differential scanning calorimetry (DSC), respectively. The interaction between blend polymers was analyzed by FTIR analysis. Gas separation performance was evaluated in terms of permeability and selectivity. FESEM results revealed that pure polymer and blend membranes were homogeneous and dense in structure. A single glass transition temperature of polymer blend membranes was found in DSC analysis which indicated the miscibility of PEI/PVAc blend. FTIR analysis confirmed the presence of molecular interaction between blend polymers. The permeation results showed that the presence of PVAc (3 wt%) in blend membranes has improved CO2 permeability up to 95% compared to pure PEI membrane. In addition, CO2/CH4 selectivity was found to be 40% higher than pure PEI membrane. This study shows that blending a small fraction of PVAc can improve the gas separation performance of PEI/PVAc blend membranes. POLYM. ENG. SCI., 59:E293–E301, 2019. © 2018 Society of Plastics Engineers
Correlation between inhomogeneity in polyacrylonitrile spinning dopes and carbon fiber tensile strength
Authors: Raghavan Vijay , Gulgunje Prabhakar V. , Gupta Kishor K. , Kamath Manjeshwar G. , Liu Yaodong , Pramanik Chandrani , Newcomb Bradley A. , Chae Han Gi , Kumar Satish
Published: November 2018

The nano‐scale and micro‐scale inhomogeneity of polyacrylonitrile (PAN) spinning dopes obtained from dynamic light scattering (DLS) experiment is correlated with the tensile strength of the resulting carbon fiber. The nanoscale inhomogeneity was estimated by calculating the diffusion coefficients from the slow relaxation mode of polymer solutions in DLS. The nanoscale inhomogeneity in the spinning dopes was found to be in the range of 1–45 nm. We also demonstrate mean of the count rate (MCR) obtained from DLS of PAN solution as a tool to detect the microscale inhomogeneity in the spinning dope for the first time. The MCR of spinning dopes varied from ~10.0 to 77.5 kcps (kilo‐counts per second). The tensile strength of carbon fibers from the precursor fiber spun from the spinning dopes in this study varied from 3 to 5.2 GPa. Correlation studies show that the microscale inhomogeneity in the spinning dope was a major contributor to the decrease in the tensile strength of carbon fibers in the range of 3–4.5 GPa. Contaminants causing microscale inhomogeneity in PAN powder were removed by using micelles, reverse micelles and frothing. The surfactant treated PAN polymer was characterized using a fourier transform infrared spectroscope, differential scanning calorimeter, and thermal gravimetic analyzer to demonstrate complete removal of surfactants. POLYM. ENG. SCI., 59:478–482, 2019. © 2018 Society of Plastics Engineers
Effect of surface roughness and reciprocating time on the tribological properties of the polyimide composites
Authors: Song Jingfu , Liu Xiaoliang , Zhao Gai , Ding Qingjun , Qiu Jinhao
Published: November 2018

Novel polyimide (PI) composites were designed and prepared as a frictional material for ultrasonic motors (USM). The effect of roughness and reciprocating time on the tribological properties of PI composites was specially investigated for simulating USM operating condition. These typical PI composites were designed along with the special characteristics of USM by filling proportional solid lubricants and nanoparticles, and prepared using classical hot‐press sintering. The friction and wear behavior of PI composites with different surface roughness polished by SiC sandpaper and various reciprocating time was carried out on a pin‐on‐plate tribo‐meter against GCr15 steel pin. The worn surface was observed by SEM to reveal wear mechanisms. Experimental results indicated that the coefficient of friction and specific wear rate increased with an increase of surface roughness which was detrimental for USM to prolong the service life. The coefficient of friction and wear volume will increase with an increase of reciprocating time due to fatigue wear, but specific wear rate will decrease with the minimum value of 2.1 × 10−6mm3/N m. This study can provide significant guidance for USM to optimize frictional surface and running‐in time. POLYM. ENG. SCI., 59:483–489, 2019. © 2018 Society of Plastics Engineers
Carbon‐centered radical initiators for polymerization of unsaturated monomers: Modeling and reactivity studies
Authors: Keaton Richard , Froese Robert D. , Ewart Sean , Spencer Liam , Pearson David , Busch Markus , Bauer Christian
Published: November 2018

A series of sterically encumbered diphenylethane molecules was examined to understand their fundamental ability to undergo homolytic bond cleavage and initiate radical polymerization of unsaturated monomers. The structures computed by density functional theory (DFT) showed a relationship between increasing C‐C bond length of the ground state molecule and reduced bond dissociation energy (BDE). The computed activation barriers associated with radical addition to acrylate were relatively low indicating that once radicals were formed, initiation of polymerization would be facile. Good correlations between computed BDE and experimentally‐determined onset temperatures for acrylate polymerization were found. The Molecule (13) with the lowest BDE (33.8 kcal/mol) determined in this work had an onset temperature of 85 °C. Ethylene polymerization failed to show a similar trend as molecules possessing the weakest C‐C bonds did not effectively initiate ethylene polymerization. Theoretical calculations demonstrated a trend in which the molecules with the lowest BDEs had the highest barriers for addition of ethylene. These barriers were significantly higher than standard peroxide initiation or chain propagation. Upon ramping the temperature, it is postulated that molecules with low BDE values form radicals but do not have sufficient energy to add to ethylene before succumbing to detrimental side‐reactions. POLYM. ENG. SCI., 59:E52–E58, 2019. © 2018 Society of Plastics Engineers