bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid, Room‐Temperature and Template‐Free Synthesis of Metal‐Organic Framework Nanowires in Alcohol
Authors: Shi Jinbiao , Zhang Jianling , Tan Dongxing , Cheng Xiuyan , Tan Xiuniang , Zhang Bingxing , Han Buxing , Liu Lifei , Zhang Fanyu , Liu Meirong , Xiang Junfeng
Published: March 2019

The well‐defined one‐dimensional nanostructures of metal‐organic frameworks (MOFs) are hard to obtain, especially for the MOF nanowires with small diameters and large lengths. Here we report a rapid, room‐temperature and template‐free route for the synthesis of MOF nanowires in alcohol. The crystallized MOF nanowires have a diameter of ∼25 nm and a length of ∼5 μm, which are highly active in catalyzing the selective aerobic oxidation of benzylic alcohol under mild conditions. The formation process and mechanism for MOF nanowires were investigated by in‐situ Fourier transformed infrared spectra and 1H nuclear magnetic resonance spectra, as well as fluorescence probe techniques. It was found that the alcohol molecules direct the assembly of MOF nanowires by hydrogen bonding with organic ligands.
Janus Interphase Organic‐Inorganic Hybrid Materials: Novel Water‐Friendly Heterogeneous Catalysts
Authors: Vafaeezadeh Majid , Breuninger Paul , Lösch Philipp , Wilhelm Christian , Ernst Stefan , Antonyuk Sergiy , Thiel Werner R.
Published: March 2019

In this work, amphiphilic silica‐based Janus‐type acid and base catalysts are introduced as heterogeneous analogues of surfactants. The new interphase organic‐inorganic hybrid catalysts comprise of two different groups (−C8H17, −C2H4Ph) on the hydrophobic and two different groups (−C3H6SO3H, −C3H6NH2) on the hydrophilic side. The hydrophobic sides of the catalysts are responsible for the diffusion of the organic substrates to the catalytically active sites while the hydrophilic sides carry catalytic centers being oriented towards the aqueous phase and thus providing sufficient connection between water (solvent) and the organic substrates. Catalyst preparation is based on simple synthetic procedures and leads in a first step to hollow silica spheres with hydrophobic groups on the inner and hydrophilic groups on the outer surface. After crushing the hollow spheres, acid resp. base functionalized Janus nano‐sheets are obtained. The basic catalyst was tested for the Knoevenagel condensation of a series of benzaldehydes with malononitrile in water, while the acid catalyst was used for Fischer esterification of acetic acid with ethanol.
Direct Conversion of Methanol to Ethanol on the Metal‐Carbon Interface
Authors: Li Yunhua , Lu Junfeng , Wang Xihui , Zhang Hua , Wu Xuee , Zhang Kelvin H. L. , Ye Jinyu , Zhan Dongping
Published: March 2019

Direct conversion of one‐carbon (C1) compounds to two‐carbon (C2) and multi‐carbon compounds remains a critical challenge for converting non‐petroleum resources to valuable chemicals or fuels. The key issue is the selective activation of C1 compounds, methanol, as well as the controlled formation of carbon‐carbon (C−C) bonds. Herein, we achieve the direct electrocatalytic methanol to ethanol, an important chemical and energy candidate, with methanol conversion, ethanol selectivity, and faradic efficiency of 257.0 g ⋅ m−2 ⋅ h−1, 95.1 %, and 12.5 %, respectively. Furthermore, the appropriate participation of water, as a by‐product from methanol electrocatalysis, in hydrogen evolution reaction (HER) facilitates electrocatalytic reaction of methanol. Mechanistic studies reveal hydroxymethyl and methyl radicals are formed on the electropositive low‐valent metal sites and electronegative carbon vacancies, respectively, and then combined with each other to form ethanol at the metal/carbon interface. This work opens a unique route for high‐efficient concerted redox conversion of methanol reactant to ethanol.
Ultrasonic Irradiation during the Calcium Sulfate Hemihydrate to Dihydrate Transformation Process
Authors: Polat Sevgi , Sayan Perviz
Published: March 2019

The ultrasound‐assisted transformation of calcium sulfate hemihydrate (CSH) to calcium sulfate dihydrate (CSD) was studied using three ultrasonic power settings. In addition to continuously measuring the variation in the conductivity value with time, the process was followed by X‐ray diffraction and scanning electron microscopy (SEM) analysis. Thermogravimetric analysis, Fourier transform infrared, mass spectrometry, and filtration analyses helped to determine the physicochemical properties of the as‐obtained crystals. The morphological changes in the surface morphology were observed by SEM. The experimental results indicate that ultrasonic irradiation and its intensity have a significant effect on the crystal size, morphology, adsorption, and filtration characteristics. Mandelic acid in combination with ultrasonic irradiation can be used as an accelerator for the transformation process from CSH to CSD.
Reducing the Interfacial Resistance in All‐Solid‐State Lithium Batteries Based on Oxide Ceramic Electrolytes
Authors: Jiang Zhouyang , Han Qingyue , Wang Suqing , Wang Haihui
Published: March 2019

All‐solid‐state lithium batteries (ASSLBs) are regarded as next‐generation advanced energy‐storage devices, owing to their high energy density and safety. The interfacial resistance is a crucial factor affecting the practical application of ASSLBs. ASSLBs based on oxide‐based ceramic electrolytes (OCEs) still exhibit poor electrochemical performance, owing to the large interfacial resistance. Area‐specific resistance values at the interfaces ranging from thousands of ohms to several ohms per square centimeter have been achieved using multiple strategies. This Review summarizes multiple existing advanced strategies used to reduce the interfacial resistance between OCEs and electrodes through interfacial engineering. We also propose some perspectives for the future development of ASSLBs based on OCEs.
Porous Isomeric Li2.5Na0.5V2(PO4)3 Wide Voltage Cathode for High‐Performance Lithium‐Ion Batteries Synthesized Through a Colloid Chemical Method
Authors: Wang Yaoyao , Zhang Xudong , He Wen , Yang Wenhao , Wei Chuanliang
Published: March 2019

The synthesis of highly active and stable cathode materials for lithium‐ion batteries (LIBs) is a major challenge for electrochemical energy storage. Herein, we report an isomeric Li2.5Na0.5V2(PO4)3 porous nanoparticle composite synthesized through a colloid chemical strategy. This composite is composed of monoclinic Li3V2(PO4)3 (M–LVP), rhombohedral Li3V2(PO4)3 (R‐LVP) and rhombohedral Na3V2(PO4)3 (R‐NVP). Benefiting from the porous structure and synergistic effects between the stable M−LVP and highly conductive R‐LVP, this composite cathode exhibits outstanding electrochemical performance for LIBs. It shows a high discharge capacity of 228.1 mAh g−1 at 0.1 C rate (1 C=150 mA g−1) and 108.9 mAh g−1 at 10 C rate in a wide potential range between 1.5 and 4.3 V. Moreover, even in a high current density of 10 C, it still exhibits a stable cycle performance and retains a discharge capacity of 80 mAh g−1 after 500 cycles.
Electrochemical Properties of 9,9′‐Spiro‐Bifluorenes Containing Group 14 Elements (C, Si, Ge, Sn)
Authors: Golub‐Sedinkin Tatiana , Herath Ajith C. , West Robert , Becker James Y.
Published: March 2019

Cyclic voltammograms of four spiro‐bifluorenes involving C (I), Si (II), Ge (III) and Sn (IV) as the central atom were recorded in acetonitrile‐dichloromethane. Each substrate afforded one irreversible oxidation wave (between 1.7 to 1.9 V, vs. Ag/AgCl) and one irreversible reduction wave between −2.0 to −2.3 V (except for the Ge derivative III that showed a second irreversible reduction wave). Controlled potential anodic oxidation was executed for II–IV on a Pt anode. Surprisingly, each one of the substrates behaved differently: II yielded biphenyl (92 %) as the major product; III afforded moderate yields of a germafluorene dimer containing Ge−Ge bond (35 %) and 1,3,5‐triphenylbenzene 10 (22 %), and IV formed the aromatic derivative 10 as the major product (76 %). In all cases, chlorinated products were formed too. A plausible mechanism for the formation of the variety of products is suggested.
Cross‐Linking Tin‐Based Metal‐Organic Frameworks with Encapsulated Silicon Nanoparticles: High‐Performance Anodes for Lithium‐Ion Batteries
Authors: Zhou Xiangyang , Yu Yawen , Yang Juan , Wang Hui , Jia Ming , Tang Jingjing
Published: March 2019

A simple one‐pot strategy is proposed to attach encapsulated Si nanoparticles to rod‐like Sn‐based metal‐organic frameworks (MOFs) through an in situ self‐assembly method. The active Sn‐MOFs amalgamating with Si nanoclusters perform their part by coordinating their individual functionalities in a complementary way. 1) As a superior capacity contributor, the rod‐like Sn‐MOFs, externally, function as a structural reinforcement that maintains the electrode integrity and mitigates the agglomeration of materials; internally, they can serve as a host material to provide inherent open channels and sufficient reserved expansion space, thus alleviating the capacity fading and further increasing the cyclability of electrodes. 2) The encapsulated Si nanoparticles not only facilitate access to a high specific capacity, but also enhance the connection between the electrode and the substrate to enable efficient electron transport upon cycling. These remarkable synergies, combined with the hybridization design, ensure that the Si@Sn‐MOF composite delivers a superior capacity as high as 1360.4 mAh g−1 at 200 mA g−1 after 250 cycles and an exceptional rate capability. When utilized as an anode material for the full cell, it exhibits a discharge capacity up to about 117.7 mAh g−1 after 150 cycles. These results reveal that such a Si@Sn‐MOF composite could be an ideal alternative anode material for high‐energy lithium‐ion batteries.
Introducing Pseudocapacitive Bioelectrodes into a Biofuel Cell/Biosupercapacitor Hybrid Device for Optimized Open Circuit Voltage
Authors: Alsaoub Sabine , Conzuelo Felipe , Gounel Sébastien , Mano Nicolas , Schuhmann Wolfgang , Ruff Adrian
Published: March 2019

We report the fabrication of a polymer/enzyme‐based biosupercapacitor (BSC)/biofuel cell (BFC) hybrid device with an optimized cell voltage that can be switched on demand from energy conversion to energy storage mode. The redox polymer matrices used for the immobilization of the biocatalyst at the bioanode and biocathode act simultaneously as electron relays between the integrated redox enzymes and the electrode surface (BFC) and as pseudocapacitive charge storing elements (BSC). Moreover, owing to the self‐charging effect based on the continuously proceeding enzymatic reaction, a Nernstian shift in the pseudocapacitive elements, that is, in the redox polymers, at the individual bioelectrodes leads to a maximized open circuit voltage of the device in both operating modes. Comparison with a conventional fuel cell design, that is, using redox mediators with redox potentials that are close to the potentials of the used redox proteins, indicates that the novel hybrid device shows a similar voltage output. Moreover, our results demonstrate that the conventional design criteria commonly used for the development of redox polymers for the use in biofuel cells have to be extended by considering the effect of a Nernstian shift towards the potentials of the used biocatalysts in those pseudocapacitive elements.
Ionic‐State Cobalt and Iron Co‐doped Carbon Dots with Superior Electrocatalytic Activity for the Oxygen Evolution Reaction
Authors: Yang Mingxi , Feng Tanglue , Chen Yixin , Zhao Xiaohuan , Yang Bai
Published: March 2019

Carbon dots (CDs), with abundant functional groups and unique electrical properties, have been widely exploited as an assistant in the preparation of metal‐based nanohybrids for electrocatalytic water splitting, but complicated synthetic procedures and high power consumption restricted their practical application. In this work, novel ionic cobalt and iron co‐doped CDs (CoFe−CDs) were synthesized in a straightforward manner through the one‐step hydrothermal treatment of cobalt gluconate and ferrous gluconate salts. The CoFe−CDs exhibited superior electrocatalytic oxygen evolution reaction activity with a small overpotential of 308 mV at a current density of 10 mA/cm2, which is comparable and even lower than those of previously reported CDs/Co, Fe‐based metal composites. The activity origin of CoII sites and the synergistic effect of FeIII within CoFe−CDs were fully understood by DFT calculations and XPS analysis, respectively. This work provides a strategy to construct active metal‐ion‐doped CDs with boosted electrocatalytic activities, and such new CDs might find potential in the field of energy storage.
Role of Water in the Reaction Mechanism and endo/exo Selectivity of 1,3‐Dipolar Cycloadditions Elucidated by Quantum Chemistry and Machine Learning
Authors: Yang Xin , Zou Jun , Wang Yifei , Xue Ying , Yang Shengyong
Published: March 2019

Asymmetric 1,3‐dipolar cycloadditions of azomethine ylides with activated olefins are among the most important and versatile methods for the synthesis of enantioenriched pyrroline and pyrrolidine derivatives. Despite both theoretical and practical importance, the role of water molecules in the reactivity and endo/exo selectivity remains unclear. To explore how water accelerates the reactions and improves the endo/exo selectivity of the cycloadditions of 1,3‐dipole phthalazinium‐2‐dicyanomethanide (1) and two dipolarophiles, an ab initio‐quality neural network potential that overcomes the computational bottleneck of explicitly considering water molecules was used. It is demonstrated that not only the nature of both the dipolarophile and the 1,3‐dipole, but also the solvent medium, can perturb or even alter the reaction mechanism. An extreme case was found for the reaction of 1,3‐dipole 1 with methyl vinyl ketone, in which the reaction mechanism changes from a concerted to a stepwise mode on going from MeCN to H2O as solvent, with formation of a zwitterionic intermediate that is a very shallow minimum on the energy surface. Thus, high stereocontrol can still be expected despite the stepwise nature of the mechanism. The results indicate that water can induce global polarization along the reaction coordinate and highlight the role of microsolvation effects and bulk‐phase effects in reproducing the experimentally observed aqueous acceleration and enhanced endo/exo selectivity.
Cobaltaelectro‐Catalyzed C—H Acyloxylation
Authors: Tian Cong , Dhawa Uttam , Struwe Julia , Ackermann Lutz
Published: March 2019

Summary of main observation and conclusion

Cobaltaelectrocatalysis set the stage for sustainable C—H acyloxylations in biomass‐derived γ‐valerolactone as a renewable solvent. The sustainable electrocatalysis regime featured ample scope, along with high levels of chemo‐ and position‐selectivity.
Development of Language in the Schülerlabor – Language‐Sensitive Teaching on the Example of Sweeteners
Authors: Haberzettl Stefanie , Huwer Johannes , Bröhl Karin , Hempelmann Rolf
Published: March 2019

Um den Herausforderungen einer heterogener werdenden Schülerschaft gerecht zu werden, müssen Unterricht und Unterrichtsmaterialien immer wieder auf den Prüfstand gestellt und aktualisiert werden. Einen solchen Ansatz bietet der sprachsensible Fachunterricht. Exemplarisch werden einige Möglichkeiten skizziert, forschendes Lernen sprachsensibel zu begleiten. Dabei liegt der Schwerpunkt auf der Vermittlung und Festigung basaler konzeptionell schriftlicher und fachsprachlicher Items und Strukturen.
Concurrent neoadjuvant chemotherapy and estrogen deprivation in patients with estrogen receptor–positive, human epidermal growth factor receptor 2–negative breast cancer (CBCSG‐036): A randomized, controlled, multicenter trial
Authors: Yu Ke‐Da , Wu Si‐Yu , Liu Guang‐Yu , Wu Jiong , Di Gen‐Hong , Hu Zhen , Hou Yi‐Feng , Chen Can‐Ming , Fan Lei , Tang Li‐Chen , Shen Zhen‐Zhou , Wu Ke‐Jin , Zhuang Zhi‐Gang , Zhang Hong‐Wei , Shao Zhi‐Ming
Published: March 2019

Background

The current randomized, controlled, multicenter clinical trial was conducted to investigate the efficacy of concurrent neoadjuvant chemotherapy (NCT) and estrogen deprivation in patients with estrogen receptor (ER)–positive, human epidermal growth factor receptor 2 (HER2)–negative breast cancer.

Methods

Eligible patients with AJCC stage IIB to stage IIIC, ER‐positive, HER2‐negative breast cancer were enrolled and randomly assigned to receive NCT with or without estrogen deprivation. The primary endpoint was the objective response rate (ORR).

Results

A total of 249 patients were assigned to either neoadjuvant chemoendocrine therapy (NCET) (125 patients) or the NCT group (124 patients). In the intention‐to‐treat analysis, the ORR was found to be significantly higher in the NCET group compared with the NCT group (84.8% vs 72.6%; odds ratio, 2.11 [95% CI, 1.13‐3.95; P = .02). The efficacy of NCET was more prominent in tumors with a higher Ki‐67 index (>20%), with an ORR of 91.2% reported in the NCET group versus 68.7% in the NCT group (P = .001). The pathologic complete response and pathological response rates did not differ significantly between the 2 groups. Although there was no significant difference with regard to progression‐free survival (PFS) between the 2 groups (P = .188), patients with a higher baseline Ki‐67 index appeared to derive a greater PFS benefit from NCET (2‐year PFS rate of 91.5% in the NCET group vs 76.5% in the NCT group; P = .058). Adding endocrine agents to NCT did not result in significant differences in adverse events (grade 3 or 4; graded according to National Cancer Institute Common Terminology Criteria for Adverse Events [version 3.0]) between the 2 groups.

Conclusions

The addition of estrogen deprivation to NCT appears to improve the clinical response in patients with ER‐positive, HER2‐negative breast cancer, especially for those individuals with a higher Ki‐67 index. Patients with a higher Ki‐67 index might derive more PFS benefit from concurrent neoadjuvant treatment.
1H NMR Chemosensing of Potassium Ions Enabled by Guest‐Induced Selectivity Switch of a Gold Nanoparticle/Crown Ether Nanoreceptor
Authors: Sun Xiaohuan , Rosa‐Gastaldo Daniele , De Biasi Federico , Rastrelli Federico , Mancin Fabrizio
Published: March 2019

A sensing protocol to detect potassium ions in water by 1H NMR spectroscopy is described. The method exploits the K+‐modulated affinity of 18‐crown‐6 functionalized gold nanoparticles towards organic ions, combined with NOE magnetization transfer. Binding of K+ to the crown ether moieties switches the nanoreceptor preference (and its ability to transfer magnetization) from organic cations (tyramine) to organic anions (phloretate). In this way, a ratiometric NMR signal is produced with a detection limit of 0.6 mM. Detection can be performed in 20 min with standard instruments and with little interference from other alkali and alkaline earth metal ions present in the sample.
Highly Polarized Benzo[k]fluoranthene Imide Derivatives: Large Solvatofluorochromism, Dual Fluorescence and Aggregation Induced Emission Associated with Excited‐State Intramolecular Charge Transfer
Authors: Katayama Kohji , Kawajiri Ikumi , Okano Yotaro , Nishida Jun‐ichi , Kawase Takeshi
Published: March 2019

The highly conjugated imides, 9‐diphenyl‐aminobenzo[k]fluoranthene imide and N‐phenylcarbazo[2,3‐k]fluoranthene imide, were produced by Buchwald‐Hartwig reaction of N‐octyl‐9,10‐dibromobenzo[k]fluoranthene imide with diphenylamine. In a similar manner, reaction of the N‐ethylhexyl‐9,10‐dibromo derivative with carbazole leads to formation of 9‐(N‐carbazoyl)benzo[k]fluoranthene imide. All the benzo[k]fluoranthene imide (BFI) derivatives in solution show remarkable solvatofluorochromism. Diphenylamino and 9‐(N‐carbazoyl) derivatives, having twisted structures, exhibit fluorescence bands at short wavelengths in highly polar solvents, and they emit dual fluorescence in acetone. Moreover, the 9‐(N‐carbazoyl) derivative displays aggregation‐induced emission in highly aqueous acetone solutions. The results of density functional theory calculations demonstrate that a considerable spatial separation exists between the HOMO and LUMO coefficients of the N‐arylamine substituted BFIs. The results indicate that the ground‐to‐excited state transitions of these compounds have intramolecular charge transfer character.
Terrestrial vertebrates as surrogates for selecting conservation areas in a biodiversity hotspot in Mexico
Authors: Monroy‐Gamboa Alina G. , Briones‐Salas Miguel Á. , Sarkar Sahotra , Sánchez‐Cordero Víctor
Published: March 2019

Systematic conservation planning (SCP) identifies priority areas for biodiversity conservation using surrogates for adequate representation of biodiversity content. The use of multiple well‐known taxonomic groups rather than single ones as a surrogate set is expected to enable a better representation of most important biodiversity constituents in prioritizing conservation areas. We quantitatively analyzed if single‐ or multitaxa groups of terrestrial vertebrates serve best as surrogates for representing biodiversity constituents in the state of Oaxaca, a biodiversity hotspot in southern Mexico. We produced species distribution models for 1,063 terrestrial vertebrate species using a maximum entropy algorithm. To determine which fraction of each terrestrial vertebrate group best represented the remaining groups, we produced solutions requiring different proportions of species to be represented with a 10% target of the species' potential distribution in conservation area networks. Precedence to geographical rarity, minimizing area, and enhancing compactness in shape of the selected priority areas was established using ConsNet. We further evaluated performance with surrogacy graphs for determining the representation of each group of terrestrial vertebrates treated as biodiversity constituents. Inclusion of multiple terrestrial vertebrate groups as surrogates performed best for the representation of biodiversity constituents compared to a single terrestrial vertebrate group, in all solutions with different proportions of species in these conservation areas. Terrestrial vertebrate species were poorly represented in the few protected areas (<2% of species), but representation increased significantly (99% of species) when complemented with other established conservation initiatives. SCP should include multitaxa surrogate sets and all established conservation initiatives to ensure priority areas for conservation with an adequate biodiversity representation.
Phloroglucinol averts isoprenaline hydrochloride induced myocardial infarction in rats
Authors: Zhu Canzhan , Li Wanjing , Wang Xinhong , Xue Jiahong , Zhao Ling , Song Yafan , Zhou Tian , Zhang Mingjuan
Published: March 2019

Myocardial infarction (MI) is indicated by the symptoms like sharp chest pain, sweating, palpitations, and nervousness finally leading to heart attack. MI occurs mainly due to the risk factors like smoking, elevated blood pressure, diabetes, hypercholesterolemia, obesity, decreased HDL level, elevated LDL level, hyperlipoproteinemia and aging consequently leads to demandable coronary blood supply, oxidative stress, and acute necrosis of the myocardium. Cardioprotective potential of the phloroglucinol (PG) was assessed by treating isoprenaline hydrochloride (ISO; 85 mg/kg b.w., s.c.) induced MI model in rats. Pretreatment with PG in a dose of 30 mg/kg was done for 28 days and followed by ISO (for MI induction) on 29th and 30th days, exhibited decline in the abnormalities in the ECG patterns, cardiac marker enzymes, enzymic and nonenzymic antioxidants, lipid peroxidation, lipid profiles, and histopathological investigations compared to isoprenaline alone treated group. On the whole, the present investigations elucidate the significance of PG in alleviating the pathological process and appreciably prevent the induction of MI in experimental rats.
Near‐infrared imaging of diseases: A nanocarrier approach
Authors: Silindir‐Gunay Mine , Sarcan Elif Tugce , Ozer Asuman Yekta
Published: March 2019

Developments in fluorescence imaging, brought popularity to near infrared (NIR) imaging with far‐red and NIR fluorophores applied for biosensing and bioimaging in living systems. Noninvasive NIR imaging gained popularity with the use of effective NIR dyes to obtain macroscopic fluorescence images. Several attributes of NIR dyes make them desirable agents, including high specificity, high sensitivity, minimized background interference, and the ability to easily conjugate with drug delivery systems. However, NIR dyes have some drawbacks and limitations, such as low solubility, low stability, and degradation. To overcome these issues, NIR dyes can be encapsulated in appropriate nanocarriers to achieve effective diagnosis, imaging, and therapy monitoring during surgery. Moreover, the vast majority of NIR dyes have photosensitizer features that can effectuate cancer treatment referred to as photodynamic therapy (PDT). In the near future, by combining NIR dyes with appropriate nanocarriers such as liposomes, polymeric micelles, polymeric nanoparticles, dendrimers, quantum dots, carbon nanotubes, or ceramic/silica based nanoparticles, the limitations of NIR dyes can be minimized or even effectively eliminated to form potential effective agents for imaging, therapy, and therapy monitoring of several diseases, particularly cancer.
Support students with mental health issues when they stop out
Authors: Hope Joan
Published: March 2019

Courtney Joly‐Lowdermilk, M.S.Ed., NITEO manager at Boston University, discussed how the NITEO program helps students with mental health conditions launch back into college.
Research suggests some professional programs might contribute to suicide risk
Authors: Sutton Halley
Published: March 2019

Veterinarians, physicians, and psychiatrists have the highest rate of suicide among all professions and a higher rate of suicide than the general population. Despite the high rate of suicides among those who work in these fields, most students who enroll in veterinary or medical school are mentally healthy and stable, suggesting that a look at the training they receive in these programs is necessary to help determine if that training causes undue stress or mental health strain, according to new research.
Inositol and antioxidant supplementation: Safety and efficacy in pregnancy
Authors: Formoso Gloria , Baldassarre Maria P.A. , Ginestra Federica , Carlucci Maria Assunta , Bucci Ines , Consoli Agostino
Published: March 2019

Pregnancies complicated by diabetes have largely increased in number over the last 50 years. Pregnancy is characterized by a physiologic increase in insulin resistance, which, associated with increased oxidative stress and inflammations, could induce alterations of glucose metabolism and diabetes. If not optimally controlled, these conditions have a negative impact on maternal and foetal outcomes. To date, one can resort only to diet and lifestyle to treat obesity and insulin resistance during pregnancy, and insulin remains the only therapeutic option to manage diabetes during pregnancy. However, in the last years, in a variety of experimental models, inositol and antioxidants supplementation have shown insulin‐sensitizing, anti‐inflammatory, and antioxidant properties, which could be mediated by some possible complementary mechanism of action. Different isomers and multiple combinations of these compounds are presently available: Aim of the present review article is to examine the existing evidence in order to clarify and/or define the effects of different inositol‐ and antioxidant‐based supplements during pregnancy complicated by insulin resistance and/or by diabetes. This could help the clinician's evaluation and choice of the appropriate supplementation regimen.
Identification of the designer steroid Androsta‐3,5‐diene‐7,17‐dione in a dietary supplement
Authors: Lorenz Lisa M. , Toomey Valerie M. , Lanzarotta Adam C. , Flurer Rick A. , Falconer Travis M.
Published: March 2019

A liquid chromatography‐mass spectrometry (LC–MS) screen for known anabolic‐androgenic steroids in a dietary supplement product marketed for “performance enhancement” detected an unknown compound having steroid‐like spectral characteristics. The compound was isolated using high performance liquid chromatography with ultraviolet detection (HPLC–UV) coupled with an analytical scale fraction collector. After the compound was isolated, it was then characterized using gas chromatography with simultaneous Fourier Transform infrared detection and mass spectrometry (GC–FT–IR–MS), liquid chromatography–high resolution accurate mass–mass spectrometry (LC–HRAM–MS) and nuclear magnetic resonance (NMR). The steroid had an accurate mass of m/z 285.1847 (error−0.57 ppm) for the protonated species [M + H]+, corresponding to a molecular formula of C19H24O2. Based on the GC–FT–IR–MS data, NMR data, and accurate mass, the compound was identified as androsta‐3,5‐diene‐7,17‐dione. Although this is not the first reported identification of this designer steroid in a dietary supplement, the data provided adds information for identification of this compound not previously reported. This compound was subsequently detected in another dietary supplement product, which contained three additional active ingredients.
Estimating the energy expenditure of free‐ranging polar bears using tri‐axial accelerometers: A validation with doubly labeled water
Authors: Pagano Anthony M. , Williams Terrie M.
Published: March 2019

Measures of energy expenditure can be used to inform animal conservation and management, but methods for measuring the energy expenditure of free‐ranging animals have a variety of limitations. Advancements in biologging technologies have enabled the use of dynamic body acceleration derived from accelerometers as a proxy for energy expenditure. Although dynamic body acceleration has been shown to strongly correlate with oxygen consumption in captive animals, it has been validated in only a few studies on free‐ranging animals. Here, we use relationships between oxygen consumption and overall dynamic body acceleration in resting and walking polar bears Ursus maritimus and published values for the costs of swimming in polar bears to estimate the total energy expenditure of 6 free‐ranging polar bears that were primarily using the sea ice of the Beaufort Sea. Energetic models based on accelerometry were compared to models of energy expenditure on the same individuals derived from doubly labeled water methods. Accelerometer‐based estimates of energy expenditure on average predicted total energy expenditure to be 30% less than estimates derived from doubly labeled water. Nevertheless, accelerometer‐based measures of energy expenditure strongly correlated (r2 = 0.70) with measures derived from doubly labeled water. Our findings highlight the strengths and limitations in dynamic body acceleration as a measure of total energy expenditure while also further supporting its use as a proxy for instantaneous, detailed energy expenditure in free‐ranging animals.
Transcriptomics and differential gene expression in Whitmania pigra (Annelida: Clitellata: Hirudinida: Hirudinidae): Contrasting feeding and fasting modes
Authors: Khan Muhammad Salabat , Guan De‐Long , Kvist Sebastian , Ma Li‐Bin , Xie Juan‐Ying , Xu Sheng‐Quan
Published: March 2019

The medicinal utility of leeches has been demonstrated through decades of use in modern hospital settings, mainly as relievers of venous congestion following flap or digit replantation surgery. In the present study, we sequence and annotate (through BLAST‐ and Gene Ontology‐based approaches) the salivary transcriptome of the nonblood feeding hirudinid Whitmania pigra and assess the differential gene expression of anticoagulation factors (through both quantitative real‐time PCR [qRT‐PCR] and in silico‐based methods) during feeding and fasting conditions. This was done in order to evince the diversity of putative anticoagulation factors, as well as estimate the levels of upregulation of genes immediately after feeding. In total, we found sequences with demonstrated orthology (via both phylogenetic analyses and BLAST‐based approaches) to seven different proteins that have previously been linked to anticoagulatory capabilities—eglin C, bdellin, granulin, guamerin, hyaluronidase, destabilase I, and lipocalin. All of these were recovered from leeches both in the fasting and in the feeding conditions, but all show signs of upregulation in the feeding leeches. Interestingly, our RNA‐seq effort, coupled with a hypergeometric test, indicated that the differentially expressed genes were disproportionately involved in three main immunological pathways (endocytosis, peroxisome regulation, and lysosome regulation). The results and implications of the finding of anticoagulants in this nonblood feeding leech and the putative upregulation of anticoagulation factors after feeding are briefly discussed in an evolutionary context.
A dam in the drylands: Soil geomorphic treatments facilitate recruitment of the endangered Santa Ana River woolly star
Authors: Hernandez Rebecca R. , Sandquist Darren R.
Published: March 2019

The long‐term management of aridland riparian ecosystems impacted by dams is crucial to reduce losses of biodiversity, reduce extinction risks for species, and restore ecosystem services. When dams preclude natural flow, safeguarding aridland riparian ecosystems adapted to infrequent, catastrophic floods poses additional challenges owing to the need to consider biological and pattern legacies. Seven Oaks Dam (California, USA) eliminated the occurrence of flooding, scouring, and deposition across the rare plant community downstream. This Riversidian alluvial fan sage scrub or alluvial scrub includes one of the most endangered plants in California, Eriastrum densifolium spp. sanctorum (Santa Ana River woolly star, hereafter called woolly star). In this study, we evaluated the impact of six soil geomorphic treatments on alluvial scrub and woolly star re‐establishment after 5, 7.5, and 13 yr. We implemented a complete randomized block design, with each block incorporating six treatments: cleared, diked, cut, filled‐10 (10 cm soil), filled‐20 (20 cm), and filled‐30 (30 cm), mimicking one or more physical disturbances (pattern legacy) occurring after a natural flood event. We performed plant community surveys (cover, abundance, maturity, invasibility, diversity) on full plots in 2006, representing 7.5 yr of response from the original 1999 treatment, and on half‐plots in 2012, representing 5 yr of response following re‐disturbance in 2007, and 13 yr of response on half‐plots left intact since 1999. We found very limited recruitment of woolly star into control plots (1.2% cover). By contrast, the cut treatment showed consistently higher cover of woolly star (25.3%, 53.4%, 14.3%), after 5, 7.5, and 13 yr, respectively. Other treatments showed responses ranging between these extremes. Similar results were found for total native cover and diversity. Woolly star cover was inversely related to alien grass cover, suggesting that exotic grass invasions inhibit early recovery of the perennial. The re‐establishment of base flows and flood pulses or soil geomorphic disturbances that mimic pattern legacies associated with infrequent, catastrophic flooding could be implemented to sustain downstream ecosystems that include woolly star populations. In the absence of such actions in the Santa Ana River floodplain, the persistence of woolly star as a species appears unlikely.
Tree recruitment dynamics in fire‐prone eucalypt savanna
Authors: Russell‐Smith Jeremy , Evans Jay , Macdermott Harry , Brocklehurst Peter , Schatz Jon , Lynch Dominique , Yates Cameron , Edwards Andrew
Published: March 2019

Savanna sites are idealized as exhibiting a demographic “bottleneck” physiognomy comprising a lower stratum of abundant resprouting persistent “juveniles” (albeit of indeterminate age), a mid‐stratum comprising relatively few released “saplings,” and a canopy‐layer cohort of “adults.” The magnitude and frequency of disturbance is considered to influence the critical transition from juvenile into adult phases. Under fire‐prone Australian savanna conditions, an extensive suite of both observational and manipulative studies have explored the responses of tree recruitment to fire disturbances. These studies oftentimes have produced seemingly highly disparate responses, particularly with respect to the differential responses of relatively fast‐growing eucalypts versus non‐eucalypts under different fire regime, and overstory competition, conditions. This study contrasts the responses of tree recruitment height classes to (1) the effects of total canopy removal from severe Cyclone Monica in 2006 over a subsequent 10‐yr period, (2) with observations from long‐term monitoring sites under relatively stable overstory conditions at Litchfield National Park over a six‐year period, (3) under ambient, frequent fire occurrence (mean > 0.5 fires/yr) at both locales including relatively severe late dry season fires. Recruitment at both study sites was represented mostly by resprouting, clonally reproducing juvenile trees <2 m tall, around half of which died over respective assessment periods. At post‐cyclone assessment plots, there was substantial release of eucalypts, including within the first five years, into the >5 m height class, with negligible corresponding release of non‐eucalypts. At Litchfield plots, there was negligible release of both eucalypts and non‐eucalypts. In discussion, we contrast these results with findings from relevant regional studies. We contend that collective disparate observations feasibly can be reconciled as reflecting significant interactions between fire regime characteristics and variable site overstory competition effects, such that the rate of recruitment of fast‐growing savanna eucalypt individuals into the midstory is relatively independent of the fire regime, but is significantly regulated by resource competition interactions especially with the overstory, whereas recruitment of non‐eucalypts is relatively independent of overstory competitive effects, but is suppressed under fire regimes dominated by frequent, especially severe fires.
Autoreactive B‐lymphocytes in SLE and RA patients: Isolation and characterisation using extractable nuclear and citrullinated antigens bound to immunobeads
Authors: de la Varga‐Martínez Raquel , Rodríguez‐Bayona Beatriz , Campos‐Caro Antonio , Añez Gustavo A , Medina‐Varo Fermín , Rodríguez Carmen
Published: March 2019

Systemic lupus erythematosus and rheumatoid arthritis are autoimmune diseases characterised by B‐cell hyperactivation and production of autoantibodies (AutoAbs) against various self‐antigens, including extractable nuclear antigens and citrullinated peptides. Therefore, B lymphocytes and antibody‐secreting cells are considered relevant targets for therapies. However, isolation and characterisation of auto‐reactive specific B lymphocytes are limited, primarily due to technical issues. In this work, we purified extractable nuclear antigen‐specific and citrullinated peptide‐specific auto‐reactive B lymphocytes by magnetic selection with ENA‐ and citrullinated peptide‐bound immunobeads. We obtained blood auto‐reactive B lymphocytes from most patients. Their nature was primarily naïve B cells, some of them in an active status, with low levels of somatic hypermutations in the immunoglobulin heavy‐chain variable regions. Their presence correlated with serum levels of autoAb. Auto‐reactive B lymphocytes were able to differentiate into auto‐reactive antibody‐secreting cells under conditions of stimulation. In addition, based on the presence of circulating auto‐reactive B cells and/or antibody‐secreting cells, four different profiles were described in lupus patients. Thus, tracking auto‐reactive B cells and/or antibody‐secreting cells in patient blood could represent a biomarker for deciding whether to use therapies blocking either B cells, plasma cells or both, as well as a new tool for monitoring minimal residual autoimmune disease in patients.
Improving the water production of a solar still by adding an internal condensation chamber: A theoretical study
Authors: Yahia Mahammed Khaled , Kerfah Rabah , Bezzina Mohamed
Published: March 2019

In this article, the validity of a numerical simulation of a basin solar still coupled with a condensation chamber was analyzed, before being cooled through a cooling water system. The system contained a serpentine pipe combined with a rectangular sheet of galvanized steel. The model was validated by comparing calculated and then experimental results mentioned in previous research for a typical day in the month of June 2013, the comparison of results showed a good agreement between the experimental and numerical tests. The model was developed to evaluate the performance of the system with optimum mass flow and compared throughout the typical day of each month of the year with that of a solar still without cooling. The model was investigated numerically according to meteorological data of the Algerian city, Khemis Miliana using the model of Capderou. The equations are modeled by the finite difference method, the Gauss–Seidel iterative method was used to solve the resulting algebraic equation. The highest productivity of the year was 6.7 Kg/m2 during the typical day of august with 60% higher productivity than the still without cooling. It was observed that the productivity of the solar still was sensitive to the flow mass of cooling water. Both the condenser chamber volume and the area from the opening of the evaporator to the condenser chamber have a significant effect on distillate production of the system. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019
Fault diagnosis of Photovoltaic Modules
Authors: Haque Ahteshamul , Bharath Kurukuru Varaha Satya , Khan Mohammed Ali , Khan Irshad , Jaffery Zainul Abdin
Published: March 2019

Fault diagnosis and condition monitoring are important to increase the efficiency and reliability of photovoltaic modules. This paper reviews the challenges and limitations associated with fault diagnosis of solar modules. A thorough analysis of various faults responsible for failure of solar modules has been discussed. After reviewing relevant work, a monitoring tool is designed using thermography and artificial intelligent systems that allows the detection of various types of faults in PV modules and at the same time the designed tool aims to filter the nonsignificant anomalies. A neural network (NN) classifier is applied to the transfer characteristics (I‐V data) of the faulty PV module for the diagnosis which adapts multilayer perceptron (MLP) networks to identify the type and location of occurring faults. The Discrete wavelet transform (DWT) based signal processing technique is utilized in the feature extraction process to reduce the NN input size. The developed detection algorithm is adapted for 24/7 automated surveillance. For a given fault condition, the average fault detection time is observed to be <9 seconds, which is lower than the previous work done. The developed algorithm achieved 100% accuracy when tested on a predetermined fault data set.
Gain of FGF4 is a frequent event in KIT/PDGFRA/SDH/RAS‐P WT GIST
Authors: Urbini Milena , Indio Valentina , Tarantino Giuseppe , Ravegnini Gloria , Angelini Sabrina , Nannini Margherita , Saponara Maristella , Santini Donatella , Ceccarelli Claudio , Fiorentino Michelangelo , Vincenzi Bruno , Fumagalli Elena , Casali Paolo Giovanni , Grignani Giovanni , Pession Andrea , Ardizzoni Andrea , Astolfi Annalisa , Pantaleo Maria Abbondanza
Published: March 2019

Gastrointestinal stromal tumors (GIST) lacking mutations in KIT/PDGFRA or RAS pathways and retaining an intact SDH complex are usually referred to as KIT/PDGFRA/SDH/RAS‐P WT GIST or more simply quadruple WT GIST (~5% of all GIST). Despite efforts made, no recurrent genetic event in quadruple WT GIST has been identified so far. To further investigate this disease, we performed high throughput copy number analysis on quadruple WT GIST specimens identifying a recurrent focal gain in band 11q13.3 (involving FGF3/FGF4) in 6/8 cases. This event was not found in the other molecular GIST subgroups. FGF3/FGF4 duplication was associated with high expression of FGF4, both at mRNA and protein level, a growth factor normally not expressed in adult tissues or in KIT/PDGFRA‐mutated GIST. FGFR1 was found to be the predominant FGF receptor expressed and phosphorylation of AKT was detected, suggesting that a FGF4‐FGFR1 autocrine loop could stimulate downstream signaling in quadruple WT GIST. Together with the recent reports of quadruple WT cases carrying FGFR1 activating alterations, these findings strengthen the hypothesis of a potential involvement of FGFR pathway deregulation in quadruple WT GIST, which may represent a rationale for novel therapeutic approaches.
Double minute chromosomes harboring MDM2 amplification in a pediatric atypical lipomatous tumor
Authors: Dadone‐Montaudié Bérengère , Burel‐Vandenbos Fanny , Soler Christine , Rosello Olivier , Boyer Corinne , Fabas Thibault , Bianchini Laurence , Pedeutour Florence
Published: March 2019

Adipocytic tumors are rare in children and are mostly benign. Less than 25 cases of pediatric well‐differentiated liposarcoma (WDLPS), atypical lipomatous tumors (ALT), and dedifferentiated liposarcoma (DDLPS) have been reported. Among them, only three cases were genetically analyzed. We describe the genetic features of a rapidly growing adipose tumor that occurred in the thigh of a 7‐year‐old girl. Histologically, it was composed of mature adipocytic cells with a few atypia. Molecular analysis showed high‐level amplification of the 12q13‐21 region including MDM2 among 64 amplified genes. MDM2 amplification is a diagnostic hallmark of ALT/WDLPS/DDLPS. In adult cases, it is typically located in ring or giant marker chromosomes. In the present case, extra‐copies of MDM2 were located on double minute chromosomes (dmin). This raised the hypothesis of dmin being precursors of adult's rings and giant markers and may provide indications for a better understanding of the mechanisms of adipose tumor oncogenesis.
Comparing MRI metrics to quantify white matter microstructural damage in multiple sclerosis
Authors: Lipp Ilona , Jones Derek K. , Bells Sonya , Sgarlata Eleonora , Foster Catherine , Stickland Rachael , Davidson Alison E. , Tallantyre Emma C. , Robertson Neil P. , Wise Richard G. , Tomassini Valentina
Published: March 2019

Quantifying white matter damage in vivo is becoming increasingly important for investigating the effects of neuroprotective and repair strategies in multiple sclerosis (MS). While various approaches are available, the relationship between MRI‐based metrics of white matter microstructure in the disease, that is, to what extent the metrics provide complementary versus redundant information, remains largely unexplored. We obtained four microstructural metrics from 123 MS patients: fractional anisotropy (FA), radial diffusivity (RD), myelin water fraction (MWF), and magnetisation transfer ratio (MTR). Coregistration of maps of these four indices allowed quantification of microstructural damage through voxel‐wise damage scores relative to healthy tissue, as assessed in a group of 27 controls. We considered three white matter tissue‐states, which were expected to vary in microstructural damage: normal appearing white matter (NAWM), T2‐weighted hyperintense lesional tissue without T1‐weighted hypointensity (T2L), and T1‐weighted hypointense lesional tissue with corresponding T2‐weighted hyperintensity (T1L). All MRI indices suggested significant damage in all three tissue‐states, the greatest damage being in T1L. The correlations between indices ranged from r = 0.18 to r = 0.87. MWF was most sensitive when differentiating T2L from NAWM, while MTR was most sensitive when differentiating T1L from NAWM and from T2L. Combining the four metrics into one, through a principal component analysis, did not yield a measure more sensitive to damage than any single measure. Our findings suggest that the metrics are (at least partially) correlated with each other, but sensitive to the different aspects of pathology. Leveraging these differences could be beneficial in clinical trials testing the effects of therapeutic interventions.