bluuebunny/crossref_metadata_2025 huggingface dataset:
Studying mass spectrometric behaviors of {Au6Ag2(C)[PPh2(4‐CH3‐Py)]6}(BF4)4 and {Au8[(PPh3)2O]3(PPh3)2}(NO3)2 by electrospray time‐of‐flight mass spectrometry and electrospray ion trap mass spectrometry
Authors: Su Hai‐Feng , Yang Jing (Jeanne) , Chen Ying , Lin Shui‐Chao , Zheng Lan‐Sun
Published: August 2016

Rationale

Mass spectrometry (MS) has been recognized as a powerful technique to detect accurate chemical information about metal clusters. Maintaining metal clusters intact, which is a great challenge in MS analysis, was achieved in this work by choosing a suitable mass analyzer and carefully optimizing analysis parameters.

Methods

Electrospray ionization time‐of‐flight mass spectrometry (ESI‐TOF‐MS) and electrospray ion trap mass spectrometry (ESI‐IT‐MS) were applied to characterize the synthesized ligand‐protected metal clusters [Au6Ag2(C)(L1)6](BF4)4 (L1 = 2‐diphenylphosphanyl‐4‐methylpyridine) (1) and [Au8(L2)3(L3)2](NO3)2 (L2 = bis(2‐diphenylphosphinophenyl)ether, L3 = triphenyl‐phosphane) (2). Three kinds of buffer gas (helium, mass: 2; nitrogen, mass: 28; argon, mass: 40) and various radiofrequency (RF) amplitudes (from 70 to 330) were chosen to study the fragmentation rate during the “collision cooling” process in the ion trap analyzer.

Results

In the ESI‐TOF‐MS analysis, metal clusters 1 and 2 were mainly observed as intact clusters, which were Au6Ag2(C)(L1)6(BF4)22+, Au6Ag2(C)(L1)6(BF4)3+, Au6Ag2(C)(L1)64+ for 1 and Au8(L2)3(L3)22+ for 2. While, in the ESI‐IT‐MS analysis, only fragments could be found, such as Au6Ag(C)(L1)6(BF4)2+, Au6(C)(L1)62+, Au5Ag(C)(L1)42+, Au6Ag(C)(L1)63+, Au(L1)+ for 1 and Au8(L2)3(L3)2+, Au8(L2)32+, Au6(L2)32+ for 2. It is obvious that the two kinds of mass analyzers caused different MS behaviors of metal clusters. In the ion trap (IT) mass analyzer, particularly, “collision cooling” was contributing to further dissociation of fragile compounds, in which a higher RF amplitude and a larger mass buffer gas led to more fragmentation.

Conclusion

In this work, intact metal clusters were obtained in ESI‐TOF‐MS, instead of ESI‐IT‐MS, in which the “collision cooling” process caused more cluster dissociation. It was concluded that the analyzer in ESI‐TOF‐MS is “softer” than that in ESI‐IT‐MS for metal clusters. Copyright © 2016 John Wiley & Sons, Ltd.
Peptide codes for multiple protease activity assay via high‐resolution mass spectrometric quantitation
Authors: Hu Junjie , Liu Fei , Feng Nan , Ju Huangxian
Published: August 2016

Rationale

Proteases, which are involved in a number of biological processes, play important roles in human health. Alterations in protease activities have been associated with many diseases. Thus, effective methods for multiple protease assay are very essential and may help to discover more about their functions in different physiological processes. Here, we proposed a strategy of peptide codes for label‐free analysis of multiple protease activities using high‐resolution mass spectrometry (HRMS).

Methods

The peptide codes were designed to contain a coding region and the substrate of the protease, respectively. Upon the cleavage of target proteases, the coding regions could be rapidly identified and directly quantitated by accurate m/z extractions without internal standard. Therefore, the coding region could be used as the unique “Protease ID” for the identification of the corresponding protease, and the amount of the cleavage product was used for protease activity analysis.

Results

The method was validated by using trypsin and chymotrypsin as model proteases, with the designed “Trypsin ID” and “Chymotrypsin ID” occurring at m/z 761.270 and 711.243, respectively. The peak area of “Protease ID” was proportional to trypsin and chymotrypsin concentration in the range from 0.01 to 10 nM and 10 to 2000 nM, respectively. The proposed method could also be used for screening of protease inhibitors, which might be of great importance for drug discovery.

Conclusions

This method provided a label‐free and accurate quantitative platform for convenient identification and activity analysis of multiple proteases, which could potentially be applied in clinical diagnosis. Copyright © 2016 John Wiley & Sons, Ltd.
Analysis of the lithiated leucosceptroids from Leucosceptrum canum to facilitate their identification and differentiation by electrospray ionization tandem mass spectrometry
Authors: Ma Feng‐Wei , Xia Bing , Luo Shi‐Hong , Li Sheng‐Hong , Zhou Yan
Published: August 2016

Rationale

Leucosceptroids, isolated from Leucosceptrum canum (L. canum), are sesterterpenoids with novel molecular scaffolds which possess potent antifeedant activities. Their molecular scaffolds comprise a 5,6,5‐framework with a great diversity due to different hydroxylation and substituent positions. The biological activities of leucosceptroids are affected by the subtle structural differences. The structural characterization and differentiation of the leucosceptroid isomers are of great importance.

Methods

Firstly, different kinds of cation adducts of leucosceptroids were examined by adding alkali metal ions to the solution, and the lithiated adducts of leucosceptroid were found to be readily formed and yielded characteristic fragment ions under collision‐induced dissociation (CID). Then, a systematic mass spectrometric investigation of the [M + Li]+ ions was carried out to clarify their characteristic fragment pathways by electrospray ionization quadrupole time‐of‐flight‐type tandem mass spectrometry (ESI‐QTOF‐MS/MS). The proposed fragmentation pathways were confirmed through ion trap ESI‐MSn (n ≥ 3) spectra. Finally, the proposed MS/MS method was applied to investigate the extracts of L. canum.

Results

A specific fragmentation pathway of the lithiated adduct, which leads to the production of diagnostic ions of leucosceptroids, was observed. This fragmentation is initiated by cleavage of the C‐ring and leads to formation of two types of ions by further dissociation. Both pathways could yield characteristic fragment ions, which could be used to define the substituents at the skeletal structure and at the C‐ring. The representative characteristic fragmentations of [M + Li]+ ions and the proposed fragmentation pathways were successfully adopted to investigate the L. canum extracts, and a total of eleven leucosceptroids were identified or tentatively characterized.

Conclusions

The characteristic fragmentation pathways of [M + Li]+ species of leucosceptroid isomers were proposed. Three types of leucosceptroid isomers were successfully differentiated. Eleven leucosceptroids were characterized from L. canum extracts. The fragmentation knowledge will facilitate the analysis of leucosceptroids and other sesterterpenoids in future research. Copyright © 2016 John Wiley & Sons, Ltd.
Comparative study of the interactions between bisphenol analogues and serum albumins by electrospray mass spectrometry and fluorescence spectroscopy
Authors: Luo Huangshi , Li Chunya , Fang Huaifang , Wang Xian
Published: August 2016

Rationale

Bisphenol A and its alternatives are widely used in common consumer products and are known as environmental endocrine disrupting chemicals. Five bisphenol analogues, namely, tetrabromobisphenol A (TBBPA), tetrachlorobisphenol A (TCBPA), 4,4′‐sulfonyldiphenol (BPS), bisphenol A (BPA) and 4,4′‐hexafluoroisopropylidenediphenol (BPAF), were selected to study their interactions with serum albumins, aiming at a better understanding of the toxicological mechanisms of bisphenol compounds.

Methods

The interactions between human and bovine serum albumins (HSA and BSA) with these five compounds were investigated by electrospray ionization mass spectrometry (ESI‐MS). Fluorescence spectroscopy and molecular docking confirmed the ESI‐MS observations and provided complementary information with respect to thermodynamic properties and binding modes.

Results

TBBPA showed the highest binding ability with HSA and BSA, followed by TBBPA and BPS, whereas BPA and BPAF exhibited little or no binding with these serum albumins. The calculated thermodynamic parameters suggested that hydrogen bonds and electrostatic forces played important roles for these interactions. Binding energies of TBBPA, TCBPA, and BPS calculated by molecular docking were −35.18, −34.39, and −25.89 kJ mol−1, respectively, in good agreement with ESI‐MS measurements.

Conclusions

The results of this study showed that halogenated substituents on the phenolic rings of bisphenol could enhance the binding ability with serum albumins. This work could provide useful information for further research on the relationship between molecular structures and toxicities of bisphenols. Copyright © 2016 John Wiley & Sons, Ltd.
Characterization of the surface properties of MgO using paper spray mass spectrometry
Authors: Zheng Yajun , Zhang Xiaoling , Bai Zongquan , Zhang Zhiping
Published: August 2016

Rationale

Significant advances have been made in the preparation of different morphologies of magnesium oxide (MgO), but the relationship between MgO morphology and its interactions with therapeutic drugs is rarely studied. Herein, we investigated the interactions between different morphologies of MgO and therapeutic drugs using paper spray mass spectrometry.

Methods

Different morphologies of MgO including trapezoidal, needle‐like, flower‐like and nest‐like structures were prepared through a facile precipitation method. The as‐obtained MgO particles were then coated onto the surface of filter paper via vacuum filtration strategy. The coated papers with different morphologies of MgO were used as the substrates for paper spray mass spectrometry to explore the interactions between different MgO and therapeutic drugs.

Results

Through investigating the interactions between different morphologies of MgO coated papers and therapeutic drugs, it demonstrated that, in contrast to the trapezoidal, needle‐like and nest‐like MgO coated papers, different drugs in dried blood spots (DBS) were more favourably eluted off from the paper coated with flower‐like MgO due to its weaker surface basicity. Also, the signal intensities of different drugs during paper spray were highly dependent on their elution behaviours.

Conclusions

Paper spray mass spectrometry (MS) provides an avenue to elaborate the surface properties of MgO with different structures. The surface basicity of MgO played a crucial role in determining the elution behaviours of therapeutic drugs in DBS, and a more favourable elution behaviour tended to result in a higher MS signal. Copyright © 2016 John Wiley & Sons, Ltd.
Application of flowerlike MgO for highly sensitive determination of lead via matrix‐assisted laser desorption/ionization mass spectrometry
Authors: Hou Jian , Chen Suming , Cao Changyan , Liu Huihui , Xiong Caiqiao , Zhang Ning , He Qing , Song Weiguo , Nie Zongxiu
Published: August 2016

Rationale

Matrix‐assisted laser desorption/ionization mass spectrometry (MALDI MS) is a high‐throughput method to achieve fast and accurate identification of lead (Pb) exposure, but is seldom used because of low ionization efficiency and insufficient sensitivity. Nanomaterials applied in MS are a promising technique to overcome the obstacles of MALDI.

Methods

Flowerlike MgO nanostructures are applied for highly sensitive lead profiling in real samples. They can be used in two ways: (a) MgO is mixed with N‐naphthylethylenediamine dihydrochloride (NEDC) as a novel matrix MgO/NEDC; (b) MgO is applied as an absorbent to enrich Pb ions in very dilute solution.

Results

The signal intensities of lead by MgO/NEDC were ten times higher than the NEDC matrix. It also shows superior anti‐interference ability when analyzing 10 μmol/L Pb ions in the presence of organic substances or interfering metal ions. By applying MgO as adsorbent, the LOD of lead before enrichment is 1 nmol/L. Blood lead test can be achieved using this enrichment process. Besides, MgO can play the role of internal standard to achieve quantitative analysis.

Conclusions

Flowerlike MgO nanostructures were applied for highly sensitive lead profiling in real samples. The method is helpful to prevent Pb contamination in a wide range. Further, the combination of MgO with MALDI MS could inspire more nanomaterials being applied in highly sensitive profiling of pollutants. Copyright © 2016 John Wiley & Sons, Ltd.
Study of G‐quadruplexes in the STAT3 gene using electrospray ionization mass spectrometry
Authors: Lin Sen , Long Haitao , Zhou Jiang , Yuan Gu
Published: August 2016

Rationale

As a key signal transducer and transcription activator, STAT3 plays a very important role in many cell processes. We found that there were many G‐rich sequences existing in the STAT3 gene including its promoter, intron, exon and 3′‐flanking regions. These G‐rich tracts can form G‐quadruplexes under near physiological conditions. In this research, we systemically studied the G‐quadruplexes in the STAT3 gene at a whole gene scale for the first time.

Methods

In this research, the formation of G‐quadruplexes in the STAT3 gene was probed by electrospray ionization mass spectrometry (ESI‐MS) and circular dichroism (CD). Their structures were constructed and refined by a molecular modeling method. We also used ESI‐MS to study the recognition of the G‐quadruplexes in the promoter of the STAT3 gene by flexible molecules which do not have a planar core like the other common quadruplex ligands.

Results

The results based on ESI‐MS suggested that the G‐quadruplexes in the promoter of the STAT3 gene formed and were further recognized by some small molecules.

Conclusion

Our research proved that the G‐rich sequences in the STAT3 gene could form G‐quadruplexes under near physiological conditions. This provides a promising target to study the regulation of cell signal transduction in vivo and drug design that aims to target STAT3 G‐quadruplexes. Copyright © 2016 John Wiley & Sons, Ltd.
Complex solution chemistry behind the simple “one‐pot” synthesis of vanadium‐substituted polyoxometalates unraveled by electrospray ionization mass spectrometry
Authors: Cao Jie , Liu Chang , Jia Qiao‐Di
Published: August 2016

Rationale

The “one‐pot” method is a deceptively simple and straightforward method for synthesis of polyoxometalates (POMs). However, the complex solution chemistry behind the simple method is neither clear nor elucidated thoroughly by a suitable method. In general, POM chemists are more focused on what final products are obtained by deliberately choosing the ingredients used in the “one‐pot” process with a limited knowledge of what is actually happening in the reaction solution.

Methods

Time‐resolved electrospray ionization mass spectrometry (ESI‐MS) was developed to monitor the dynamic solution speciation changes occurred in the reaction mixtures ({SiW12‐x} (x = 1–3) + NaVO3) against reaction time. The reactions were conducted as normal, with 2 μL aliquots removed at specific time intervals during the reaction. The aliquots were immediately diluted with 1 mL of HPLC grade water and then analyzed by ESI‐MS. As a control, solutions of each {SiW12‐x} were analyzed alongside the vanadium reactions to corroborate which fragments were due to the lacunary precursors and which were due to the reactions with sodium metavanadate.

Results

It was discovered that the reaction solution speciation was sensitively changed with the reaction conditions such as concentration, temperature, and reaction time. Spontaneous transformations from mono‐ into di‐ and eventually tri‐substituted products ({SiW11V} → {SiW10V2} → {SiW9V3}) were observed for the reactions of {SiW11} + VO3− and {SiW10} + VO3−, respectively. Higher concentration and temperature definitely accelerate the transformation reaction rates whereas different molar ratios of reactants have minimal effects on changing the solution speciation in the cases studied.

Conclusions

Time‐resolved ESI‐MS is effectively and successfully used in the monitoring of the dynamic speciation changes in the reaction mixtures consisting of lacunary POMs with transition salts. This study will provide guidance for the oriented design and controlled synthesis of POMs with novel structures. Copyright © 2016 John Wiley & Sons, Ltd.
Multi‐channel cell co‐culture for drug development based on glass microfluidic chip‐mass spectrometry coupled platform
Authors: Wu Jing , Jie Mingsha , Dong Xueling , Qi Hongbin , Lin Jin‐Ming
Published: August 2016

Rationale

Cell‐based drug assay plays an essential role in drug development. By coupling a microfluidic chip with mass spectrometry (MS), we developed a multifunctional platform. Cell co‐culture, cell apoptosis assay, fluorescence and MS detection of intracellular drug absorption could be simultaneously conducted on this platform.

Methods

Three micro‐channels were fabricated through photolithography technology to conduct the cell co‐culture. Cell apoptosis after drug treatment was assayed by fluorescent probes (Hoechst 33342). Intracellular Dox absorption was analyzed by confocal fluorescent microscopy. With a high voltage (~ 4.5 kV) applied onto the microfluidic chip, the ionization spray was successfully generated by dropping isopropanol onto it. By coupling with a Shimadzu LCMS‐2010 A mass spectrometer, intracellular CPA absorption was detected on the microfluidic chip.

Results

The microfluidic chip‐MS coupled platform showed high biocompatibility. Distinction of cell apoptosis between co‐cultured and mono‐cultured cells was detected. The results of intracellular drug absorption well explained the different cell apoptosis rate.

Conclusions

Cell‐based drug assay was facilely and successfully conducted on the microfluidic chip‐MS coupled platform. This technology we have devised could promote MS application in the field of drug development. Copyright © 2016 John Wiley & Sons, Ltd.
Identification of hydroxylation at aromatic amino acid residues in yeast kinase using mass spectrometry with affinity enrichment
Authors: Zheng Shuzhen , Bai Xue , Tian Shanshan , Wang Guojuan , Zhai Guijin , Guo Zhenchang , Bi Wenjing , Shen Lijin , Zhang Kai
Published: August 2016

Rationale

Protein kinases represent the key elements in phosphorylation‐based signal transmission. Recent studies suggest that hydroxylation may mediate activities of protein kinases. This paper aims to examine the hydroxylation in protein kinases for improving our understanding of the protein modification.

Methods

We combined affinity‐based protein purification with MS analysis for identification of novel hydroxylation at aromatic amino acid residues in yeast kinases.

Results

We identified 17 hydroxylation at aromatic amino acid residues (10 at Phe, 1 at Tyr and 6 at Trp) using MS analysis. We further characterized the localization and studied the potential significance of these modifications.

Conclusions

This is a new report on the identification of hydroxylation at aromatic amino acid residues in yeast kinases. This study expands the catalog of hydroxylation in kinases and suggests the potential function of hydroxylation. Copyright © 2016 John Wiley & Sons, Ltd.
Rapid analysis and identification of meat species by laser‐ablation electrospray mass spectrometry (LAESI‐MS)
Authors: Zhou Wenzhao , Xia Lei , Huang Chaoqun , Yang Jingwei , Shen Chengyin , Jiang Haihe , Chu Yannan
Published: August 2016

Rationale

Laser‐ablation electrospray ionization mass spectrometry (LAESI‐MS) was applied to analyze fresh meat species without sample pretreatment. The study demonstrates that the LAESI‐MS technique is a promising, rapid and accurate method for meat identification using a protocol combining principal component analysis (PCA) and partial least squares discriminant analysis (PLS‐DA).

Methods

A focused IR‐laser was used for meat sample ablation at a wavelength of 2940 nm. The ablated particulates were carried through a transfer PTFE tube using air as carrier gas, delivered to the electrospray plume and ionized. A TOF‐MS was used to detect the ion signal. The raw mass spectra were analyzed using the PCA and PLS‐DA protocol.

Results

Five fresh meat samples, chicken, duck, pork, beef and mutton, were identified by the developed LAESI‐MS technique using the protocol combining PCA and PLS‐DA. The discrimination accuracy of all meat species is 100%, and the score plot also shows good identifying ability.

Conclusions

Five fresh meat samples were analyzed using the LAESI‐MS technique. Each set of raw mass data was collected within 30 s and analyzed by the PCA and PLS‐DA protocol. Eighteen, 19, 18, 17, and 15 markers for chicken, duck, pork, beef, and mutton, respectively, have been selected successfully for meat identification. The results demonstrate that LAESI‐MS is a new reliable and rapid method for meat identification. Copyright © 2016 John Wiley & Sons, Ltd.
Morphometric measurement of the cervical spine for minimally invasive pedicle screw fixation using reverse engineering and three‐dimensional reconstruction
Authors: Zhou Zi‐Jia , Wen Chao‐Lun , Sun Qin‐Min , Wang Ai‐Ping , Yan Zheng‐Guang , Liu Fang , Chen Xi , Cao Qi , Zhou Xiao‐Bing , Tan Jian‐Guo , Li Yan‐Bing
Published: August 2016

Background

Percutaneous cervical pedicle screw fixation has been proven to be an effective method of cervical screw instrumentation, which has the advantages of less invasiveness and low blood loss. Emerging evidence has indicated that the cervical spinous process plays an important role in percutaneous spine surgery. However, there is a limited amount of information on the fundamental research of pedicle and its associated imaging parameter measurement. The purpose of this study was to measure the anatomic data of the pedicle screw channel (PSC) using reverse engineering and three‐dimensional reconstruction, and also to discuss the three‐dimensional relationship between the cervical spinous process and the pedicle screw channel.

Methods

Twenty adult subjects (10 males, 10 females, age range 19–46 years) were studied using the method of three‐dimensional CT reconstruction and reverse engineering. The centrum was divided into 10 equal parts from front to back. The bisectors were defined as borderline depths of the centrum, from front to back, 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 0% of borderline depths were presented. Then, a 3D coordinate system was constructed to measure all the data, including the radius of the inscribed circle, the length of the PSC, the insertion angle, the distances from entry point to cervical spinous process and skin depth. All the indexes were measured from 70% to 90% borderline depth.

Results

The radius of the inscribed circles from C3 to C7 at 90% borderline depth were 2.94 ± 0.55 mm, 3.04 ± 0.40 mm, 3.15 ± 0.36 mm, 3.28 ± 0.47 mm, 3.89 ± 0.54 mm, respectively. The lengths of the PSC were between 25 and 32 mm. The insertion angles for 70% to 90% borderline depth were 28.33°, 34.28°, 37.92°, respectively. The relationship between the PSC and spinous process was measured as the distance from the entry point to the end of the spinous process, which were, respectively, 26.91 mm, 28.18 mm, 30.03 mm, 35.67 mm, 41.99 mm from C3 to C7.The distance from the skin to the entry point of C3‐7 increased gradually.

Conclusions

The measurements of this study could provide detailed information for percutaneous cervical screw fixation. The data of the relationship between the cervical spinous process and the pedicle screw channel present valuable technical information for the design, optimization and clinical application of the aiming device for percutaneous cervical pedicle screw fixation. Copyright © 2016 John Wiley & Sons, Ltd.
A virtual‐reality simulator and force sensation combined catheter operation training system and its preliminary evaluation
Authors: Wang Yu , Guo Shuxiang , Tamiya Takashi , Hirata Hideyuki , Ishihara Hidenori , Yin Xuanchun
Published: August 2016

Background

Endovascular surgery benefits patients because of its superior short convalescence and lack of damage to healthy tissue. However, such advantages require the operator to be equipped with dexterous skills for catheter manipulation without resulting in collateral damage. To achieve this goal, a training system is in high demand.

Methods

A training system integrating a VR simulator and a haptic device has been developed within this context. The VR simulator is capable of providing visual cues which assist the novice for safe catheterization. In addition, the haptic device cooperates with VR simulator to apply sensations at the same time. The training system was tested by non‐medical subjects over a five days training session.

Results

The performance was evaluated in terms of safety criteria and task completion time. The results demonstrate that operation safety is improved by 15.94% and task completion time is cut by 18.80 s maximum. Moreover, according to subjects′ reflections, they are more confident in operation.

Conclusions

The proposed training system constructs a comprehensive training environment that combines visualization and force sensation. Copyright © 2016 John Wiley & Sons, Ltd.
Piperic Acid Amide of β,β‐disubstituted‐β‐Amino Acid, 2‐(4‐Amino‐1‐Benzylpiperidin‐4‐yl)Acid [β3, 3‐Pip(Bzl)] as Cytotoxic and Apoptosis Inducing Agent
Authors: Wani Naiem Ahmad , Rasool Reyaz ur , Farooq Saleem , Shankar Sudha , Amin Hina , Nayak Debasis , Koul Surrinder , Goswami Anindya , Rai Rajkishor
Published: August 2016

Piperic acid (PA) and 4‐ethylpiperic (EPA) amides with non‐protein amino acids were synthesized and bioevulated by using MTT [3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide] assay against a panel of three cancer cell lines i. e. human prostate cancer (PC‐3), pancreatic cancer (Panc‐1) colorectal carcinoma (HCT‐116) and a normal prostate cell line BPH‐1. Among all the tested compounds, C3 exhibited promising cytotoxicity against pancreatic cancer (Panc‐1) cell line with IC50 of 7.0 μM and it showed very mild cytotoxic effect on BPH‐1 cells. In addition, the cell growth inhibition and apoptopic induction by C3 was investigated in pancreatic cancer cells by using western‐blot analysis, of PARP‐1 and caspase‐3 cleavage along with DAPI staining and caspase glow assay. The compound arrested the Panc‐1 cells in G2 phase of cell cycle. The mechanistic investigation revealed that C3 blocks the p‐38‐MAPK/ERK1/2, a strong prosurvival pathway. These results demonstrate that compound C3 has a potential antiproliferative and apoptosis inducing effects in Panc‐1 cells.
Fabrication of CuS@Ni3S4‐ polyacrylonitrile textile fabric with enhanced reusability for the treatment of dyes wastewater
Authors: Pan Wei , Huang Yuanhui , Cui Shizhong , Chen Weihua , Mi Liwei
Published: August 2016

A novel functional polyacrylonitrile(PAN) fabric coated pineapple‐like CuS@Ni3S4 heterojunctions were successfully fabricated via a simple chemical bath deposition and solvothermal pathway. Through field‐emission scanning electron microscopy (FE‐SEM) and X‐ray diffraction (XRD), the obtained CuS@Ni3S4 composites were characterized. The as‐prepared CuS@Ni3S4 were composed of numerous ultrthin nanosheets interconnect with each other to form pineapple‐like structure. According to the photocatalytic measurements, it was observed that the obtained PAN@CuS@Ni3S4 composites exhibit significantly enhanced photocatalytic activity for the degradation of methylene blue (MB) compared to the primary PAN@CuS under UV light illumination. Moreover, CuS@Ni3S4 supported on the flexible PAN fabric exhibits good reusability, indicating that this sort of materials have a high potential application in the photodegradation of dyes in wastewater treatment.
Honey‐Based P, N and Si Tri‐Doped Graphitic Carbon Electrocatalysts for Oxygen Reduction Reaction in Alkaline Conditions
Authors: Ramasahayam Sunil Kumar , Viswanathan Tito
Published: August 2016

A serious quest exists to develop sustainable electrocatalysts for facilitating O2 reduction reaction (ORR) due to the serious shortcomings of precious metal/metal oxide based electrocatalysts. In this study, we report novel honey based N, P and Si tri‐doped electrocatalysts developed by a robust, one‐step microwave assisted method. The method is unique, simple, inexpensive, high yielding and environment friendly. Ammonium polyphosphate, a good microwave absorber was utilized as the N and P source and silicone fluid was utilized as the Si source. Three different electrocatalysts were prepared, namely, PNSiDC‐1, PNSiDC‐2 and PNSiDC‐3. BET (Brunauer‐Emmett‐Teller) surface area analysis revealed high surface areas of 421 m2 g−1, 425 m2 g−1 and 524 m2 g−1 for PNSiDC‐1, PNSiDC‐2 and PNSiDC‐3 respectively with pore volumes above 0.2 cm3 g−1. XPS analysis confirmed the presence of N, P, O and Si dopants in a predominant C matrix in all PNSiDCs. The ORR performance of the electrocatalysts improved towards a complete 4 electron process from PNSiDC‐1 to −3 as the dopant concentrations, surface area and porosity increased. RRDE (Rotating Ring Disk Electrode) studies also suggest a 4 electron ORR as there is no evidence of significant ring current. Electrochemical stability studies performed with PNSiDC‐3 indicate the durability of the developed electrocatalysts as there is no significant loss of ORR activity over 2000 continuous cycles.
Synthesis, Structures and Conformational Studies of 1,2‐Dimethyl[2.10]metacyclophan‐1‐enes
Authors: Akther Thamina , Islam Md Monarul , Rahman Shofiur , Georghiou Paris E. , Matsumoto Taisuke , Tanaka Junji , Thuéry Pierre , Redshaw Carl , Yamato Takehiko
Published: August 2016

A series of 1,2‐dimethyl[2.10]metacyclophan‐1‐enes (MCP‐1‐enes) containing different substituent groups has been synthesized to illustrate their conformational behavior. 4,22‐dimethoxy‐1,2‐dimethyl[2.10]MCP‐1‐ene 3 was synthesized by a Grignard coupling reaction, Friedel‐Crafts acylation reactions and McMurry coupling reaction from 1,10‐dibromodecane. The formation of 4,22‐dihydroxy‐1,2‐dimethyl[2.10]MCP‐1‐ene 4 was carried out by demethylation of compound 3 with boron tribromide at room temperature. The syn type conformation of 4 was characterized by X‐ray diffraction and was found to form both intramolecular and intermolecular hydrogen bonds between the two hydroxyl groups. From this reaction an interesting compound [10]tetrahydrobenzofuranophane 5 was afforded on prolonging the reaction time. 5,21‐diformyl‐4,22‐dihydroxy‐1,2‐dimethyl[2.10]MCP‐1‐ene 6 has been prepared from 4,22‐dihydroxy‐1,2‐dimethyl[2.10]MCP‐1‐ene 4 by using the Duff method in the presence of hexamethylenetetramine. Structural analysis by 1H NMR spectroscopy and X‐ray diffraction confirmed that both the solution and the crystalline state of compound 6 adopts an anti‐conformation which forms an intramolecular hydrogen bond between the formyl group and the hydroxyl group, which is an interesting finding for long carbon chain MCP compounds.
Discovery of Unprecedented Ion–exchange Behavior of Nanometric Scheelite Prepared from Single‐Source Precursors
Authors: Perkins Cory K. , Apblett Allen W.
Published: August 2016

Water‐soluble precursors for nanometric calcium tungstate (CaWO4) were prepared from calcium 2‐hydroxycarboxylate salts. The precursors decompose as low as 425 °C to yield nanocrystalline scheelite. Supported CaWO4 in a convenient form for water treatment processes was prepared by impregnation of high surface area catalyst support pellets with an aqueous solution of a single‐source precursor followed by drying and calcining. Both the powder and supported nanocrystalline forms of CaWO4 underwent ion‐exchange reaction with aqueous lead ions whereby Ca2+ was released and Pb2+ was adsorbed to produce crystalline stolzite (PbWO4). Electron microscopy demonstrated that little morphological change of the particles occurred upon reaction with excess Pb2+. The process appears to occur via an ion‐exchange route. The nonlinear pseudo first‐order kinetic model gave the best fit for both the powder and supported forms of CaWO4, allowing the kinetic results from the two materials to be directly compared to each other. Supporting of CaWO4 improves the kinetics at higher CaWO4:Pb2+ ratios while at lower ratios diffusion of the Pb2+ ions into the porous pellets likely becomes the controlling factor and the powder form uptakes Pb2+ faster. The molar capacity of the material for Pb2+ uptake improved from 70 % to 100 % upon supporting the CaWO4. The novel ion‐exchange materials were demonstrated to be useful for the purification of industrial wastewaters and juice.
Multilayer Edible Fresh–keeping Films’ Characterization and Their Preservation Effect
Authors: Liu Xuefan , Zhu Yanxi , Ren Jiaoyu , Xuan Hongyun , Zhang Jianhao , Ge Liqin
Published: August 2016

Edible films help to extend the shelf‐life of fruits by preventing moisture loss and improving other aspects that related to the complex postharvest process of fruits. The layer‐by‐layer (LBL) deposition method offers a promising way to prepare functional multilayer films with controllable properties. In this study, three types of edible films based on chitosan (CS), sodium alginate (SA), sodium carboxymethyl cellulose (CMC) and sodium polyacrylate (PAAS) were fabricated using the LBL technique. Properties such as morphology, water solubility, water permeability, mechanically properties and transmittance were studied on the films. Glycerol (Gly) was added to the surface of these films. Gly increased the smoothness and transmittance of films and decreased the edible films’ water solubility, water vapor permeability and tensile strength. Films formed with CMC, CS and glycerol showed the best performance in the preservation effect of tangerines, as firmness and weight loss ratio inhibition were observed on tangerines coated with (CMC/CS)3/Gly film.
Direct Synthesis and Antimicrobial Evaluation of Structurally Complex Chalcones
Authors: Patil Vikrant , Barragan Enrique , Patil Shivaputra A. , Patil Siddappa A. , Bugarin Alejandro
Published: August 2016

A variety of chalcone derivatives were synthesized via aldol condensation of diverse aldehydes with acyclic and cyclic ketones, under mild reaction conditions. Reaction yields of pure products fluctuated from 48 % to 81 %. An unusually wide range of substrates including quinolines, thiophenes, pyridines, and fluorinated compounds were synthesized for this study. Full characterization data, along with in vitro antimicrobial activity for all adducts, are herein reported. Whole cell growth inhibition assays against staphylococcus aureus, escherichia coli, klebsiella pneumonia, acinetobacter baumannii, pseudomonas aeruginosa, candida albicans and cryptococcus neoformans var. grubii were performed employing all synthesized compounds (3a–m).
A Pyridine – Containing Fluorescent Probe for the Detection of Trivalent Cations in Aqueous Medium and in the Solid State
Authors: Beneto Arockiam Jesin , Siva Ayyanar
Published: August 2016

Selective detection of trivalent cations such as Al3+, Cr3+, Fe3+ colorimetrically and ratiometrically were measured in solution by intramolecular charge transfer (ICT) induced by binding of proton with large stoke′s shift. The detection and color changes happened in quick response of time and easily visible to the naked eye. In solid state, when the fluorophore jb2 contacted with trivalent cations fluorescence switching happened, the fluorphore can easily anchored on the silica and recognition is possible by dipping into the trivalent cations and the signaling was occurring even in micromolar level. This proton binding signalling can be reversed by alkaline solutions into solution as well as in solid media. This fluorogenic switching behavior in solvent free condition is offered the promising field in various applications.
Incipient Twisted Ribbon Structure Stabilized by C12 Helical Turns in γ4/α Hybrid Peptide
Authors: Shankar Sudha , Wani Naiem Ahmad , Singh Umesh Prasad , Rai Rajkishor
Published: August 2016

The present work describes the synthesis and crystallographic analysis of γα hybrid peptides, Boc‐γ4‐L‐Phe‐L‐Pro‐NHMe (P1) and Boc‐(γ4‐L‐Phe‐L‐Pro)2‐NHMe (P2). Peptide P1 adopts twelve membered (C12) helical turn over γα segment, while P2 folds into twisted ribbon structure involving two expanded C12 helical turns.
Conformational Shift of a β‐Hairpin Peptide upon Complex Formation with an Oligo–proline Peptide Studied by Mass Spectrometry
Authors: Kölbel Knut , Warnke Stephan , Seo Jongcheol , von Helden Gert , Moretti Rocco , Meiler Jens , Pagel Kevin , Sinz Andrea
Published: August 2016

So‐called super‐secondary structures such as the β‐hairpin, studied here, form an intermediate hierarchy between secondary and tertiary structures of proteins. Their sequence‐derived ‘pure’ peptide backbone conformation is combined with ‘remote’ interstrand or interresidue contacts reminiscent of the 3D‐structure of full‐length proteins. This renders them ideally suited for studying potential nucleation sites of protein folding reactions as well as intermolecular interactions. But β‐hairpins do not merely serve as model systems; their unique structure characteristics warrant a central role in structural studies on their own. In this study we applied photo cross‐linking in combination with high‐resolution mass spectrometry and computational modeling as well as with ion mobility‐mass spectrometry to elucidate these structural properties. Using variants of a known β‐hairpin representative, the so‐called trpzip peptide and its ligands, we found evidence for a conformational transition of the β‐hairpin and its impact on ligand binding.
One‐Pot Microwave‐Assisted Synthesis of Reduced Graphene Oxide/Iron Oxide Nanocomposite Catalyst for the Oxygen Reduction Reaction
Authors: Garino Nadia , Sacco Adriano , Castellino Micaela , Muñoz‐Tabares José A. , Armandi Marco , Chiodoni Angelica , Pirri Candido F.
Published: August 2016

We report on a reliable and eco‐friendly procedure for the synthesis of reduced graphene oxide/Fe2O3 nanocomposite via a fast microwave‐assisted one‐pot reduction and functionalization of graphene oxide. Morphology, structure and electrochemical behavior of the as‐prepared material were characterized through different techniques. Structural and morphological characterizations evidenced the formation of nanocomposite sheets, with iron oxide nanoparticles integrated in the graphene matrix. Physico‐chemical analysis revealed the functionalization of the graphene also by the presence of nitrogen atoms that show synergistic catalysis effects with Fe2O3. Electrochemical characterizations put in evidence the ability of such material to exploit competitive performances for the oxygen reduction reaction, comparable to Pt‐based catalysts, commonly used for fuel cell applications.
Implantation of Stromal Vascular Fraction Progenitors at Bone Fracture Sites: From a Rat Model to a First-in-Man Study
Authors: Saxer Franziska , Scherberich Arnaud , Todorov Atanas , Studer Patrick , Miot Sylvie , Schreiner Simone , Güven Sinan , Tchang Laurent A.H. , Haug Martin , Heberer Michael , Schaefer Dirk J. , Rikli Daniel , Martin Ivan , Jakob Marcel
Published: August 2016

Stromal Vascular Fraction (SVF) cells freshly isolated from adipose tissue include osteogenic- and vascular-progenitors, yet their relevance in bone fracture healing is currently unknown. Here, we investigated whether human SVF cells directly contribute to the repair of experimental fractures in nude rats, and explored the feasibility/safety of their clinical use for augmentation of upper arm fractures in elderly individuals. Human SVF cells were loaded onto ceramic granules within fibrin gel and implanted in critical nude rat femoral fractures after locking-plate osteosynthesis, with cell-free grafts as control. After 8 weeks, only SVF-treated fractures did not fail mechanically and displayed formation of ossicles at the repair site, with vascular and bone structures formed by human cells. The same materials combined with autologous SVF cells were then used to treat low-energy proximal humeral fractures in 8 patients (64-84 years old) along with standard open reduction and internal fixation. Graft manufacturing and implantation were compatible with intraoperative settings and led to no adverse reactions, thereby verifying feasibility/safety. Biopsies of the repair tissue after up to 12 months, upon plate revision or removal, demonstrated formation of bone ossicles, structurally disconnected and morphologically distinct from osteoconducted bone, suggesting the osteogenic nature of implanted SVF cells. We demonstrate that SVF cells, without expansion or exogenous priming, can spontaneously form bone tissue and vessel structures within a fracture-microenvironment. The gained clinical insights into the biological functionality of the grafts, combined with their facile, intra-operative manufacturing modality, warrant further tests of effectiveness in larger, controlled trials.
Suppression of reactive oxygen species‐mediated ERK and JNK activation sensitizes dihydromyricetin‐induced mitochondrial apoptosis in human non‐small cell lung cancer
Authors: Kao Shang‐Jyh , Lee Wei‐Jiunn , Chang Jer‐Hwa , Chow Jyh‐Ming , Chung Chi‐Li , Hung Wen‐Yueh , Chien Ming‐Hsien
Published: August 2016

Nonsmall cell lung cancer (NSCLC) is the most common type of lung cancer with a high mortality rate and still remains a therapeutic challenge. A strategy for targeting NSCLC is to identify agents that are effective against NSCLC cells while sparing normal cells. Dihydromyricetin (DHM) is the major flavonoid component derived from Ampelopsis grossedentata, which has a long history of use in medicine. Herein, the molecular mechanisms by which DHM exerts its anticancer effects against NSCLC cells were investigated. Results from MTS, colony formation, Western blot, flow cytometric, and JC‐1 mitochondrial membrane potential assays revealed that DHM showed a selective cytotoxic effect against NSCLC cells (A549 and H1975), but not against normal lung (WI‐38) fibroblasts, by inducing apoptosis. DHM‐induced cell apoptosis occurred through Bcl‐w suppression‐mediated mitochondrial membrane depolarization, caspase‐9/‐7/‐3 activation, and poly(ADP‐ribose) polymerase (PARP) cleavage in A549 and H1975 cells. Moreover, treatment of A549 and H1975 cells with DHM induced increase of intracellular peroxide and sustained activation of extracellular signal‐regulated kinase (ERK)1/2 and c‐Jun N‐terminal kinase (JNK)1/2, and the reactive oxygen species scavenger, N‐acetylcysteine (NAC), reversed DHM‐induced ERK and JNK activation. Furthermore, treatment of cells with specific inhibitors of ERK and JNK or NAC significantly promoted the DHM‐induced activation of caspase‐9/‐7/‐3 and PARP cleavage and also sensitized the antitumorigenic effect of DHM on NSCLC cells. These findings define and support a novel function of DHM of inducing mitochondrion‐derived apoptosis in human NSCLC cells, and a combination of DHM with ERK and JNK inhibitors should be a good strategy for preventing NSCLC proliferation. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1426–1438, 2017.
Prediction of stillbirth from placental growth factor at 19–24 weeks
Authors: Aupont J. E. , Akolekar R. , Illian A. , Neonakis S. , Nicolaides K. H.
Published: August 2016

Objectives

To investigate whether the addition of maternal serum placental growth factor (PlGF) measured at 19–24 weeks' gestation improves the performance of screening for stillbirth that is achieved by a combination of maternal factors, fetal biometry and uterine artery pulsatility index (UtA‐PI) and to evaluate the performance of screening with this model for all stillbirths and those due to impaired placentation and unexplained or other causes.

Methods

This was a prospective screening study of 70 003 singleton pregnancies including 268 stillbirths, carried out in two phases. The first phase included prospective measurement of UtA‐PI and fetal biometry, which were available in all cases. The second phase included prospective measurement of maternal serum PlGF, which was available for 9870 live births and 86 antepartum stillbirths. The values of PlGF obtained from this screening study were simulated in the remaining cases based on bivariate Gaussian distributions, defined by the mean and standard deviations. Multivariable logistic regression analysis was used to determine whether the addition of maternal serum PlGF improved the performance of screening that was achieved by a combination of maternal factors, fetal biometry and UtA‐PI.

Results

Significant contribution to the prediction of stillbirth was provided by maternal factor‐derived a‐priori risk, multiples of the median values of PlGF, UtA‐PI and fetal biometry Z‐scores. A model combining these variables predicted 58% of all stillbirths and 84% of those due to impaired placentation, at a false‐positive rate of 10%. Within the impaired‐placentation group, the detection rate of stillbirth < 32 weeks' gestation was higher than that of stillbirth ≥ 37 weeks (97% vs 61%; P < 0.01).

Conclusions

A high proportion of stillbirths due to impaired placentation can be identified effectively in the second trimester of pregnancy using a combination of maternal factors, fetal biometry, uterine artery Doppler and maternal serum PlGF. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.
Climate service warnings: cautions about commercializing climate science for adaptation in the developing world
Authors: Webber Sophie , Donner Simon D
Published: August 2016

This article examines the increasing emphasis amongst climate scientists and development professionals on providing ‘climate services’ in order to inform adaptation decisions in vulnerable countries. The climate service business model hopes to provide ‘on demand’ and ‘actionable’ information products that are useful for policy makers. Drawing from literature across the natural and social sciences, we outline potential benefits and limits of this model of providing climate information and products, as well as recommendations for improving climate services. We argue that a shift away from the commercialized model of climate services may be necessary to ensure the creation, and consistent delivery, of products that practitioners in the developing world are able to employ in making adaptation decisions. WIREs Clim Change 2017, 8:e424. doi: 10.1002/wcc.424

This article is categorized under:

Climate and Development > Knowledge and Action in Development

Social Status of Climate Change Knowledge > Climate Science and Decision Making
Inhibition of Human Group IIA‐Secreted Phospholipase A2 and THP‐1 Monocyte Recruitment by Maslinic Acid
Authors: Yap Wei Hsum , Ahmed Nafees , Lim Yang Mooi
Published: August 2016

Maslinic acid is a natural pentacyclic triterpenoid which has anti‐inflammatory properties. A recent study showed that secretory phospholipase A2 (sPLA2) may be a potential binding target of maslinic acid. The human group IIA (hGIIA)‐sPLA2 is found in human sera and their levels are correlated with severity of inflammation. This study aims to determine whether maslinic acid interacts with hGIIA‐sPLA2 and inhibits inflammatory response induced by this enzyme. It is shown that maslinic acid enhanced intrinsic fluorescence of hGIIA‐sPLA2 and inhibited its enzyme activity in a concentration‐dependent manner. Molecular docking revealed that maslinic acid binds to calcium binding and interfacial phospholipid binding site, suggesting that it inhibit access of catalytic calcium ion for enzymatic reaction and block binding of the enzyme to membrane phospholipid. The hGIIA‐sPLA2 enzyme is also responsible in mediating monocyte recruitment and differentiation. Results showed that maslinic acid inhibit hGIIA‐sPLA2‐induced THP‐1 cell differentiation and migration, and the effect observed is specific to hGIIA‐sPLA2 as cells treated with maslinic acid alone did not significantly affect the number of adherent and migrated cells. Considering that hGIIA‐sPLA2 enzyme is known to hydrolyze glyceroacylphospholipids present in lipoproteins and cell membranes, maslinic acid may bind and inhibit hGIIA‐sPLA2 enzymatic activity, thereby reduces the release of fatty acids and lysophospholipids which stimulates monocyte migration and differentiation. This study is the first to report on the molecular interaction between maslinic acid and inflammatory target hGIIA‐sPLA2 as well as its effect towards hGIIA‐sPLA2‐induced THP‐1 monocyte adhesive and migratory capabilities, an important immune‐inflammation process in atherosclerosis.