bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ambient ionization mass spectrometry applied to new psychoactive substance analysis
Authors: Boronat Ena Maria del Mar , Cowan David A. , Abbate Vincenzo 
Published: May 2021

AbstractIn the past decade a plethora of drugs with similar effects to controlled psychoactive drugs, like cannabis, amfetamine (amphetamine), or lysergic acid diethylamide, have been synthesized. These drugs can collectively be classified under the term new psychoactive substances (NPS) and are used for recreational purposes. The novelty of the substances, alongside the rapid rate of emergence and structural variability, makes their detection as well as their legal control highly challenging, increasing the demand for rapid and easy‐to‐use analytical techniques for their detection and identification. Therefore, interest in ambient ionization mass spectrometry applied to NPS has grown in recent years, which is largely because it is relatively fast and simple to use and has a low operating cost. This review aims to provide a critique of the suitability of current ambient ionization techniques for the analysis of NPS in the forensic and clinical toxicology fields. Consideration is given to analytical performance and ease of implementation, including ionization efficiency, selectivity, sensitivity, quantification, analyte chemistry, molecular coverage, validation, and practicality.
A microstrip bandpass filter with tunable bandwidth and center frequency
Authors: Chen Anrong , Yang Tao 
Published: May 2021

AbstractThis paper presents a bandwidth and center frequency tunable bandpass filter with wide tuning range. The proposed filter employs two cascade cross‐shaped resonators. The cross‐shaped resonator can generate two independent tunable transmission zeros by introducing two microwave varactors. The center frequency and bandwidth can be tuned by adjusting the DC bias voltages applied to the varactors. For demonstration, a filter example was designed, fabricated and measured. The tuning 3‐dB bandwidth from 20% to 30% is achieved when the center frequency is tuned from 3.5 to 5 GHz. Meanwhile the insertion loss is less than 4 dB with a high selectivity. The size of the filter is 0.32λg × 0.36λg where λg is the guided‐wavelength at the center frequency.
Fully automated treatment planning for MLC‐based robotic radiotherapy
Authors: Schipaanboord Bastiaan W.K. , Giżyńska Marta K. , Rossi Linda , de Vries Kim C. , Heijmen Ben J.M. , Breedveld Sebastiaan 
Published: May 2021

PurposeTo propose and validate a fully automated multicriterial treatment planning solution for a CyberKnife® equipped with an InCiseTM 2 multileaf collimator.MethodsThe AUTO BAO plans are generated using fully automated prioritized multicriterial optimization (AUTO MCO) of pencil‐beam fluence maps with integrated noncoplanar beam angle optimization (BAO), followed by MLC segment generation. Both the AUTO MCO and segmentation algorithms have been developed in‐house. AUTO MCO generates for each patient a single, high‐quality Pareto‐optimal IMRT plan. The segmentation algorithm then accurately mimics the AUTO MCO 3D dose distribution, while considering all candidate beams simultaneously, rather than replicating the fluence maps. Pencil‐beams, segment dose depositions, and final dose calculations are performed with a stand‐alone version of the clinical dose calculation engine. For validation, AUTO BAO plans were generated for 33 prostate SBRT patients and compared to reference plans (REF) that were manually generated with the commercial treatment planning system (TPS), in absence of time pressure. REF plans were also compared to AUTO RB plans, for which fluence map optimization was performed for the beam angle configuration used in the REF plan, and the segmentation could use all these beams or only a subset, depending on the dosimetry.ResultsAUTO BAO plans were clinically acceptable and dosimetrically similar to REF plans, but had on average reduced numbers of beams ((beams in AUTO BAO)/(beams in REF) (relative improvement): 24.7/48.3 (−49%)), segments (59.5/98.9 (−40%)), and delivery times (17.1/22.3 min. (−23%)). Dosimetry of AUTO RB and REF were also similar, but AUTO RB used on average fewer beams (38.0/48.3 (−21%)) and had on average shorter delivery times (18.6/22.3 min. (−17%)). Delivered Monitor Units (MU) were similar for all three planning approaches.ConclusionsA new, vendor‐independent optimization workflow for fully automated generation of deliverable high‐quality CyberKnife® plans was proposed, including BAO. Compared to manual planning with the commercial TPS, fraction delivery times were reduced by 5.3 min. (−23%) due to large reductions in beam and segment numbers.
Dominant and recessive congenital myasthenic syndromes caused by SYT2 mutations
Authors: Maselli Ricardo A. , Wei David T. , Hodgson Trent S. , Sampson Jacinda B. , Vazquez Jessica , Smith Heather L. , Pytel Peter , Ferns Michael 
Published: May 2021

AbstractIntroduction/AimsWe studied a patient with a congenital myasthenic syndrome (CMS) caused by a dominant mutation in the synaptotagmin 2 gene (SYT2) and compared the clinical features of this patient with those of a previously described patient with a recessive mutation in the same gene.MethodsWe performed electrodiagnostic (EDX) studies, genetic studies, muscle biopsy, microelectrode recordings and electron microscopy (EM).ResultsBoth patients presented with muscle weakness and bulbar deficits, which were worse in the recessive form. EDX studies showed presynaptic failure, which was more prominent in the recessive form. Microelectrode studies in the dominant form showed a marked reduction of the quantal content, which increased linearly with higher frequencies of nerve stimulation. The MEPP frequencies were normal at rest but increased markedly with higher frequencies of nerve stimulation. The EM demonstrated overdeveloped postsynaptic folding, and abundant endosomes, multivesicular bodies and degenerative lamellar bodies inside small nerve terminals.DiscussionThe recessive form of CMS caused by a SYT2 mutation showed far more severe clinical manifestations than the dominant form. The pathogenesis of the dominant form likely involves a dominant‐negative effect due to disruption of the dual function of synaptotagmin as a Ca2+‐sensor and modulator of synaptic vesicle exocytosis.
Numerical investigation of flow control technology for grouting and blocking of flowing water in karst conduits
Authors: Xu Zhenhao , Pan Dongdong , Lin Peng , Zhang Qingsong , Li Haiyan , Zhang Yichi 
Published: May 2021

AbstractA sequential flow and solidification method was applied to the numerical investigation of flow control technology for grouting and blocking of flowing water in karst conduits. This method accounted for the temporal‐ and spatial‐evolution characteristics of the viscosity. It achieved the visualization of grouting in flowing water in a conduit, and was used to explore a reasonable and effective method for grouting through flow‐control technology. Firstly, the responses of different water tables and flow‐control intensities were studied by establishing a generalized model of flow control at the outlet of a conduit. Secondly, the initial sedimentation location and the distance of down‐flow and counter‐flow of slurries with different intensities of flow control were compared and analyzed. The outlet flow, the loss rate of the slurry, and the distribution laws of velocity and pressure inside the conduit during plugging were further analyzed. In addition, the mechanism of flow control for the grouting and plugging of large‐flow conduits was revealed. The results showed that the most direct effect of flow control on grouting was to decrease the flow rate of flowing water, and the most essential role was to improve the retention rate of slurry. Moreover, the results were applied to the large‐scale water inrush control project of Hejing Limestone Mine, China. The slurry stop devices improved the retention rate of slurry and optimized the grouting technology, which had a certain guiding significance in the treatment of water‐inrush disasters in karst areas.
Effect of open versus closed endotracheal suctioning on intracranial pressure in severe brain‐injured children: Study protocol for a randomized controlled trial
Authors: Li Yan , Li Xiaoyan , Wen Zunjia , Zhang Xin , Liu Yingfei , Wei Li 
Published: May 2021

AbstractAimTo compare the effects and safety of open and closed endotracheal suction in children with severe brain injury.DesignA single‐blinding, single‐centre randomized controlled trial (RCT).MethodsThe children with severe brain injury admitted to the intensive care unit (ICU) from 1 September 2020–31 August 2022 will be included. And a total of 172 children with severe brain injury are expected to be included. The intracranial pressure, SpO2and heart rate before suctioning, at the end of suction, and at 5 and 10 min after suction, the estimated sputum volume for each suction, the incidence of ventilator‐associated pneumonia, the duration of mechanical ventilation and the length of ICU stay will be analysed.ResultsThis present RCT has been prospectively registered in China Clinical Trial Registry (http://www.chictr.org.cn, ChiCTR2000030963). This present study is expected to provide reliable evidence to the airway management in children with severe brain injury.
Combination of peptides with biological, organic, and inorganic materials for synergistically enhanced diagnostics and therapeutics
Authors: Kim Joo‐Young , Lee Jae Yun , Park Ha Yeon , Kim Hyunji , Kang Jeon Hyeong , Kim Hyun Jin , Jeong Woo‐Jin 
Published: May 2021

AbstractArmed with the useful properties of small molecules and proteins, peptides hold the potential to be utilized in almost all biomedical research fields. However, the clinical application of peptides has been limited due to their intrinsic drawbacks, such as poor plasma stability and low target binding affinity. The conjugation of peptides to biological, organic (nonbiological), and inorganic materials has recently emerged as a promising strategy to address these problems. Hence, in this article, we provide an overview of the successful outcomes of using peptide‐bio/organic/inorganic conjugates in various biomedical applications, including the diagnosis and treatment of diseases.
Effects of solar cell group granularity and modern system architectures on partial shading response of crystalline silicon modules and systems
Authors: Sinapis Kostas , Rooijakkers Tom T. H. , Pacheco Bubi Rafael , van Sark Wilfried G. J. H. M. 
Published: May 2021

AbstractPartial shading is widely considered to be a limiting factor in the performance of photovoltaic (PV) systems applied in urban environments. Modern system architectures combined with per module deployment of power electronics have been used to improve performance especially at heterogeneous irradiance conditions. In this work another approach is used to combine modern system architecture with alternate module designs. The granularity of cell groups in PV modules is investigated together with the so‐called Tessera concept, in which single cells are cut in 16 parts. Typical meteorological year yield calculations show that these alternate module designs in combination with modern system architectures can retrieve up to half the shading losses compared to standard modules and string inverters under identical shading conditions.
Physical decoloration in the concentration process of natural rubber
Authors: Rojruthai Porntip , Pareseecharoen Chayaporn , Sakdapipanich Jitladda 
Published: May 2021

AbstractNatural rubber (NR) latex contains many components, especially non‐rubber components, which can affect the color of products made from it. There is a growing demand in NR products which are lightly colored or color filled. One way to reduce the yellow color of NR is to remove non‐rubber components, for example, lipids and proteins, from NR. This study focused on several NR latex decoloration techniques, including controlling centrifugation speed and time as well as percentage of total solid content (% TSC) of field latex. It was found that the best condition to reduce yellow color was centrifugation of the field latex containing less than 35% TSC at 12,000 rpm for 30 min. In addition, decoloration of NR latex was very effective by washing the centrifuged latex at least twice. Other factors, such as storage time and drying conditions, promoted coloration of NR due to the oxidation of the non‐rubbers.
Three chemosensory proteins from the sweet potato weevil, Cylas formicarius, are involved in the perception of host plant volatiles
Authors: Hua Jinfeng , Fu Yujie , Zhou Qiaoling , Huang Yongmei , Li Huifeng , Chen Tianyuan , Ma Daifu , Li Zongyun 
Published: May 2021

AbstractBACKGROUNDChemosensory proteins (CSPs) play important roles in chemical communication, but their precise physiological functions are still unclear. Cylas formicarius is the most serious pest attacking sweet potato around the world. At present, there is no effective way to control this pest.RESULTSOur results showed that CforCSP1, 5 and 6 genes were highly expressed in the antennae of both sexes of C. formicarius. In addition, results from a fluorescence competitive binding assay showed that the CforCSP1, 5 and 6 proteins had high binding affinities for 17 plant volatiles including eight host plant volatiles. This indicated that the three proteins may be involved in the detection of host plant volatiles. Furthermore, results from four‐arm olfactometer bioassays showed that there was a significant tendency for C. formicarius to be attracted to eucalyptol, β‐carotene, benzaldehyde, vanillin and phenethyl alcohol, while it was repelled by β‐ionone. Finally, the levels of expression of the three CforCSPs in C. formicarius were successfully inhibited by RNA interference (RNAi). Behavioral experiments showed that CforCSP1, 5 and 6‐deficient C. formicarius were partly anosmic to β‐cyclocitral, benzaldehyde, octyl aldehyde, and β‐ionone and exhibited a reduced ability to locate the host plant volatiles β‐carotene and vanillin.CONCLUSIONOur data suggest that CforCSP1, 5 and 6 likely are involved in the chemical communication between C. formicarius and host plant volatiles, which may play pivotal roles in oviposition and feeding site preferences. More importantly, these results could provide information for the development of monitoring and push‐pull strategies for the control of C. formicarius. © 2021 Society of Chemical Industry.
Autophagy inhibition enhances anti‐pituitary adenoma effect of tetrandrine
Authors: Lyu Liang , Hu Yu , Yin Senlin , Wang Li , Ye Feng , Wang Mengmeng , Zhou Yueling , Ma Weichao , Chen Cheng , Jiang Yong , Wang Zeming , Jiang Shu , Zhou Peizhi , Wang Xiujie 
Published: May 2021

Pituitary adenoma (PA) is a benign intracranial neoplasm originated from pituitary gland. Surgery is the first‐line therapy for most of PAs, but lead to unsatisfactory prognosis in some cases. Tetrandrine (Tet) has anticancer effect on some cancers. However, growth inhibition effect on PA is unknown. To elucidate the inhibitory effect of Tet on the growth of PA and its potential mechanisms, we validated the in vitro and in vivo anti‐PA effect of Tet and illustrated the cellular and molecular alterations by confocal microscopy observation, flow cytometry, and RNA interference. Tet inhibited PA cell growth in vitro and tumor progression in vivo. Tet induced autophagy and apoptosis in a dose‐dependent manner. Low dosage (1.25 μM) of Tet induced PA cell autophagy by down‐regulation of MAPK/STAT3 signal. While, higher dosage (5.0 μM) of Tet partially induced PA cell death through caspase‐dependent apoptosis. Autophagy inhibitors enhanced Tet‐induced caspase activity and apoptotic cell death. These findings demonstrated that Tet has anti‐PA effect by inducing autophagy and apoptosis through MAPK/STAT3 signaling pathway attenuation and autophagy inhibition might enhance its anti‐PA effect, indicating that Tet (or combined with autophagy inhibitor) is a potential therapeutic regimen for PAs.
A unique sequential C–S or N–S inductive cleavage and retro‐Diels‐Alder fragmentation mechanism for alkylsulfonyl piperidine‐ and piperazine‐containing compounds
Authors: Maw Hlaing H. , Teitelbaum Aaron M. , Yu Hongbin 
Published: May 2021

RationaleBI 605906 undergoes a collision‐induced dissociation (CID) fragmentation resulting in the loss of methylsulfinic acid and butadiene to produce a corresponding imine. The fragmentation is hypothesized to occur via inductive cleavage of the C–S bond, generating a six‐membered cyclic ene, followed by the retro‐Diels‐Alder (RDA) reaction. The aim of this study was to provide mechanistic evidence for the proposed fragmentation by investigating the CID spectra of BI 605906 and other alkylsulfonyl piperidine‐ and piperazine‐containing compounds.MethodsThe positive electrospray ionization tandem mass spectrometric (ESI+‐MS/MS) fragmentations of BI 605906, D9‐BI 605906, GK02935, GK02942, ketoconazole, terazosin, and homopiperazine were investigated. Additionally, incubations of BI 605906 and GK02942 in human liver microsomes (HLM) preparations were conducted. Metabolite identification experiments were performed following these incubations to investigate corresponding in vitro metabolism.ResultsBI 605906, D9‐BI 605906, GK02935, and GK02942 demonstrated the same fragmentation pattern by generating a respective imine ion, supporting the hypothesized inductive cleavage and subsequent RDA mechanism. Ketoconazole and terazosin, which contain either an N‐acetyl or tetrahydrofuranyl piperazine group, respectively, did not demonstrate this mechanism, notably because they do not have the alkylsulfonyl moiety as a good leaving group. Although homopiperazine contains an arylsulfonyl diazepane group, and the initial step produced an unsaturated diazepane ring, the subsequent RDA reaction was unable to proceed due to the absence of a six‐membered cyclic ene intermediate. Additionally, we identified oxidative metabolites of BI 605906 and GK02942 in HLM incubations utilizing the proposed fragmentation pattern.ConclusionsIn the mass spectrometer, compounds containing alkylsulfonyl piperidine or piperazine groups can undergo inductive cleavage, leading to a six‐membered cyclic ene intermediate. This intermediate will then form a corresponding imine ion via the RDA reaction. A practical application of this work is to utilize this fragmentation for elucidating structures of metabolites arising from parent compounds containing alkylsulfonyl piperidine or piperazine moieties.
Investigations of β‐carotene radical cation formation in infrared matrix‐assisted laser desorption electrospray ionization (IR‐MALDESI)
Authors: Bagley M. Caleb , Muddiman David C. 
Published: May 2021

RationaleRadical cationization of endogenous hydrocarbons in cherry tomatoes was previously reported using infrared matrix‐assisted laser desorption electrospray ionization (IR‐MALDESI), a mass spectrometry imaging technique that operates at ambient conditions and requires no sample derivatization. Due to the surprising nature of this odd‐electron ionization, subsequent experiments were performed on β‐carotene to determine the amount of radical cationization across different sampling conditions.Methodsβ‐Carotene was analyzed across a variety of sample states using IR‐MALDESI followed by Orbitrap mass spectrometric analysis: first, as a standard in ethanol in a well plate; second, as particulates on printer paper; and third, as particulates covered by an ice matrix. These techniques were also performed with a β‐carotene standard either in solution with a reducing agent (ascorbic acid) or with ascorbic acid in the electrospray solution.ResultsTandem mass spectrometry confirmed the presence of the radical cation of β‐carotene by comparing fragments against NIST and METLIN databases. It was always analyzed as a radical cation when sampled from solution, where ascorbic acid increased radical cation abundance when in solution with β‐carotene. Mixed‐mode ionization between radical cationization and proton adduction was observed from dried particulates using IR‐MALDESI.ConclusionsThere are several potential mechanisms for β‐carotene radical cationization prior to IR‐MALDESI analysis, with multiphoton ionization, thermal degradation, and/or reaction with oxygen appearing to be the most logical explanations. Furthermore, although not the primary cause, changing certain aspects of sample conditions can result in significant mixed‐mode ionization with competing protonation.
Pulmonary AL amyloidosis and multiple myeloma presenting as cough with diffuse pulmonary opacities
Authors: Xu Alan , Lawton Emily , Smith Steven , Kalro Akash , Geake James 
Published: May 2021

AbstractAmyloidosis is an uncommon multisystem disease that can affect many organs. However, interstitial lung involvement is very rare. A 68‐year‐old man presented with long‐standing dyspnoea and productive cough. After extensive investigation, including two non‐diagnostic bronchoscopies, a surgical lung biopsy demonstrated pulmonary amyloidosis. A bone marrow biopsy confirmed multiple myeloma. The patient was treated with chemotherapy and an autologous stem cell transplant.
Pleural effusion secondary to chronic pancreatitis in childhood
Authors: Lim Adeline Y. L. , Gauld Leanne M. 
Published: May 2021

AbstractPleural effusion secondary to a pancreatico‐pleural fistula is a very rare presentation in children, with limited reports in the literature. We describe two differing presentations of pleural effusions resulting from chronic pancreatitis (CP) with successful resolution of the pleural effusion. These cases highlight the need for consideration of this rare paediatric diagnosis, and the variety of investigations, management strategies, and complications that can occur in the setting of CP in children.
A robotized handheld smart tool for orthopedic surgery
Authors: Hung Shuo‐Suei , Hsu Alex Shao‐Feng , Ho Tsung‐Han , Chi Chau‐Hwa , Yen Ping‐Lang 
Published: May 2021

AbstractBackgroundHandheld surgical robots offer functionalities, such as active guidance, tremor suppression and force reflection, for surgeons to enhance their skill in manipulating surgical tools during medical intervention. In orthopedic surgery, the robot additionally has to offer sufficient rigidity and power for bone machining. The size and weight of the mechanical design, together with the control behaviour associated with involuntary hand motion, navigation and reflected force to the human, all influence the overall performance of an orthopedic handheld robot.MethodsThe paper proposes a miniature and compact design for an embedded robot, which is a similar weight as a handpiece. Then, a shared controller is proposed to address the coupling among involuntary and voluntary hand motions, robot navigation, tool feedback forces and force artefacts from actuation.ResultsThe handheld robot is able to stabilize the drill positioning by removing involuntary tremors as well as reduce force artefacts from motor actuation in experiments involving pedicle tunnelling on a porcine spine.ConclusionThe paper has successfully realized a compact handheld orthopedic robot which provides high performance of usability, tremor suppression and force reflection for bone drilling.
Random triangles in random graphs
Authors: Heckel Annika 
Published: May 2021

AbstractIn a recent paper, Oliver Riordan shows that for and p up to and slightly larger than the threshold for a Kr‐factor, the hypergraph formed by the copies of Kr in G(n, p) contains a copy of the binomial random hypergraph with . For r = 3, he gives a slightly weaker result where the density in the random hypergraph is reduced by a constant factor. Recently, Jeff Kahn announced an asymptotically sharp bound for the threshold in Shamir's hypergraph matching problem for all . With Riordan's result, this immediately implies an asymptotically sharp bound for the threshold of a Kr‐factor in G(n, p) for . In this note, we resolve the missing case r = 3 by modifying Riordan's argument. This means that Kahn's result also implies a sharp bound for triangle factors in G(n, p).