bluuebunny/crossref_metadata_2025 huggingface dataset:
To Be or Not to Be: Demystifying the 2nd‐Quantized Picture of Complex Electronic Configuration Patterns in Chemistry with Natural Poly‐Electron Population Analysis
Authors: Kyriakidou Katerina , Karafiloglou Padeleimon , Glendening Eric , Weinhold Frank
Published: February 2019

We provide a didactic introduction to 2nd‐quantized representation of complex electron–hole (e/h) excitation patterns in general configuration interaction wave functions built from orthonormal local orbitals of natural atomic orbital or natural bond orbital (NBO) type. Such local excitation patterns of chemically oriented basis functions can be related to the resonance concepts of valence bond theory, and quantitative evaluation of the associated excitation probabilities then provides an alternative assessment of resonance “weighting” that may be compared with those of NBO‐based natural resonance theory. We illustrate the usefulness of anticommutation relations in deriving Pauli‐compliant expressions for allowed excitation patterns, showing how the exciton‐like promotions φλ → φν (creating an e/h excitation with h in φλ and e in φν) impose strict constraints on associated e/h‐probabilities (requiring, e.g., that the e‐probability for an electron “to be” or “not to be” in φν must be rigorously linked to the complementary h‐probabilities in φλ). Specific examples are presented of the quantum Boolean logic for four or six local spin‐orbitals, with emphasis on Natural Poly‐Electron Population Analysis (NPEPA) evaluation of VB‐type covalent and ionic contributions in conventional 2‐center bonding, resonance weightings in 3‐center hydrogen bonding, and general characteristics of higher‐order m‐center bonding motifs for m > 3. Numerical results are presented for methylamine, acrolein, and water dimer to illustrate current NPEPA implementation in the NBO program. © 2019 Wiley Periodicals, Inc.
Next‐generation sequencing improves molecular epidemiological characterization of thalassemia in Chenzhou Region, P.R. China
Authors: Zhang Haoqing , Li Caiyun , Li Jianbiao , Hou Shuai , Chen Danjing , Yan Haiying , Chen Shiping , Liu Saijun , Yin Zhenzhen , Yang Xiaoqin , Tan Jufang , Huang Xiaoyan , Zhang Liming , Fang Junbin , Zhang Caifen , Li Wei , Guo Jian , Lei Dongzhu
Published: February 2019

Objectives

Thalassemia is a highly prevalent monogenic inherited disease in southern China. It is important to collect epidemiological data comprehensively for proper prevention and treatment.

Methods

In this study, blood samples collected from 15 807 residents of Chenzhou were primarily screened by hematological tests. A total of 3973 samples of suspected thalassemia carriers were further characterized by combined next‐generation sequencing (NGS) and Gap‐PCR.

Results

In total, 1704 subjects were diagnosed as thalassemia carriers with a total prevalence rate of 10.78%, including 943 α‐thalassemia carriers, 708 β‐thalassemia carriers, and 53 composite α and β‐thalassemia carriers. The prevalence rates of α‐thalassemia, β‐thalassemia, and composite α and β‐thalassemia were 5.97%, 4.48%, and 0.34%, respectively. Meanwhile, we characterized 19 α‐thalassemia variations and 21 β‐thalassemia variations in thalassemia carriers. Approximately 2.88% of thalassemia carriers would be missed by traditional genetic analysis. In addition, four novel thalassemia mutations and one novel abnormal hemoglobin mutation were identified.

Conclusions

Our data suggest a high prevalence of thalassemia and a diverse spectrum of thalassemia‐associated variations in Chenzhou. Also, combined NGS and Gap‐PCR is an effective thalassemia screening method. Our findings might be helpful for prevention and treatment of thalassemia in this region.
What makes a difficult patient so difficult? Examining the therapist's experience beyond patient characteristics
Authors: Fischer Candice , Cottin Marianne , Behn Alex , Errázuriz Paula , Díaz Ruben
Published: February 2019

The primary aim of this study is to improve our understanding of therapists’ experience of a “difficult patient” and consider the different variables involved in this label. What makes a patient be perceived as difficult by a therapist in public health services? Results of our analysis of 10 qualitative semistructured interviews of therapists working in public health service in Chile indicated that therapists’ perceptions of a “difficult patient” depend on variables that go beyond the patient's intrinsic characteristics, including patients’ negative attitude toward the therapist and treating team, patients’ negative effects on therapists, and a difficult treatment context (e.g., work overload, scarce resources, limited number, and frequency of sessions). We illustrate the interaction of these dimensions and focus on the impact of the treating context on therapists’ experience of a “difficult patient” through the case of a therapist working with a patient with complex depression in the public health system of Chile.
Dentinal tubule penetration of endodontic sealers after nonthermal plasma treatment: A confocal laser scanning microscopy study
Authors: Gunes Betul , Yeter Kubra Y. , Terlemez Arslan , Seker Basak , Altay Yasin
Published: February 2019

One of the factors affecting the success of endodontic treatment is to fill the root canal system hermetically. The aim of this in vitro study was to evaluate the effect of nonthermal plasma (NP) on dentinal tubule penetration of root canal sealers using confocal laser scanning microscopy. Forty mandibular premolar teeth were selected and the root canals were prepared with large‐Waveone‐Gold rotary‐files. Specimens were divided into four experimental groups according to sealer and NP treatment (n = 10). G1: AH‐Plus (AH) G2: nonthermal plasma application + AH‐Plus(AH‐P) G3: Endosequence‐BC(BC) G4: nonthermal plasma application + Endosequence‐BC(BC‐P). Cold lateral‐condensation technique was used for the obturation of root canals. The roots were sectioned horizontally and the sections were examined under confocal laser scanning microscopy. The maximum tubule penetration and percentage of penetration values were obtained from the microscopy images and were statistically analyzed with repeated measurements‐ANOVA and the Tukey (HSD) test (p < 0.05). The percentages of dentinal tubule penetration of the groups were not statistically different. The maximum tubule penetration of the AH‐P was statistically lower than that of the BC‐P (p < 0.05). Plasma application had no affect on the percentage of dentinal tubule penetration. Under the conditions of this in vitro Endosequence‐BC sealer showed higher maximum tubule penetration values than AH‐Plus after NP treatment. Percentage of dentinal tubule penetration values of experimental groups was similar.
Functionalized magnetic nanoparticles attenuate cancer cells proliferation: Transmission electron microscopy analysis
Authors: Akhtar Sultan , Khan Firdos Alam , Buhaimed Abdullah
Published: February 2019

The penetration and transportation of nanoparticles (NPs) inside the cancer cells is critical to study. In this article, cancer cells (HCT‐116) were treated with functionalized magnetic NPs for the period of 48 hr and studied their ultrastructure by transmission electron microscopy (TEM). The NPs‐treated cells were prepared by chemical fixation and sliced into electron‐transparent arbitrary sections (200 × 200 μm2) by ultramicrotome. Major events of NPs–cell interaction, such as penetration of NPs, encapsulation of NPs into the intracellular compartments, transportation of NPs, and NPs exit, were examined by TEM to understand the mechanism of cell death. The NPs showed the uniform spherical shape with broad size distribution (100–400 nm), while cells displayed irregular morphology with average diameter ~5 μm. Our results showed the successful penetration of NPs deep into the cell, encapsulation, transportation, and exocytosis. Furthermore, we tested the different concentrations (0, 1.5, 12.5, and 50 μg/ml) of NPs on cancer cells and evaluated the cell viability. Laser confocal microscopy and colorimetric analysis together demonstrated that the cell viability is a dose‐dependent phenomenon, where 50 μg/ml specimen showed the highest killing of cancer cells compared to other dosages.
Clozapine‐induced myocarditis: Follow‐up for 3.5 years after successful retrial
Authors: Otsuka Yuji , Idemoto Keita , Hosoda Yutaka , Imamura Yukitsugu , Aoki Tsutomu
Published: February 2019

Schizophrenia patients have significantly lower life expectancy than the general population. Clozapine is the most effective antipsychotic to reduce the mortality rate in these patients. Here, we report a schizophrenic patient with clozapine‐induced myocarditis and successful retrial. In the first trial, clozapine was discontinued due to myocarditis. In the second trial, the titration rate was slower, and sodium valproate was not coadministered with clozapine. The patient has not developed myocarditis over 3.5 years of observation. It may be possible to take clozapine for a long time even after clozapine‐induced myocarditis, and thus improve the life expectancy of schizophrenia patients.
Senescent cells: Living or dying is a matter of NK cells
Authors: Antonangeli Fabrizio , Zingoni Alessandra , Soriani Alessandra , Santoni Angela
Published: February 2019

NK cells are lymphocytes of the innate immune system, which are able to deal promptly with stressed cells. Cellular senescence is a cell stress response leading to cell cycle arrest that plays a key role during tissue homeostasis and carcinogenesis. In this review, how senescent cells trigger an immune response and, in particular, the ability of NK cells to recognize and clear senescent cells are discussed. Special attention is given to the NK cell-mediated clearance of senescent tumor cells. NK cells kill senescent cells through a mechanism involving perforin- and granzyme-containing granule exocytosis, and produce IFN-γ following senescent cell interaction, leading to hypothesize that NK cell-mediated immune clearance of senescent cells not only relies on direct killing but also on cytokine production, that in turn can promote macrophage activation. These aspects, as well as the ability of the senescence-associated secretory phenotype and senescent cell-produced extracellular vesicles to modulate NK cell effector functions, are described.
Numerical evaluation of permanent magnet‐assisted synchronous reluctance rotor topologies using a simplified magnetostatic model
Authors: Neusüs Sascha , Binder Andreas
Published: February 2019

Permanent magnet (PM)‐assisted synchronous reluctance rotor topologies are investigated by a simplified magnetostatic finite element method (FEM) model. In this model, the slotted stator structure of an original 11‐kW standard cage induction motor is replaced by an air‐gap winding and an iron yoke to avoid time‐consuming transient numerical simulations. The rotor consists of three rectangular shaped ferrite magnets and field line‐shaped rotor flux barriers. A rotor parametrization is shown that enables the use of optimization methods. The simplified model allows then to analyze the electromagnetic torque, the internal power factor, and the PM demagnetization. Thus, different rotor variants are compared using a multi‐objective (electromagnetic torque and internal power factor) genetic optimization algorithm. The number of rotor variables (height, width, and radial position of each PM) can be reduced with low impact on these objectives. The electromagnetic torque ripple is also taken into account for the final rotor variant by using a slotted stator model.
Functionalized nanoparticles containing MKP‐1 agonists reduce periodontal bone loss
Authors: Valerio Michael S. , Alexis Frank , Kirkwood Keith L.
Published: February 2019

Background

Progress over of the past several years has elucidated a role for mitogen‐activated protein kinase phosphatase to regulate periodontal inflammation yielding new possibilities for treatment of periodontal diseases. These studies aimed to determine if nanoparticles (NPs) loaded with a pharmacological agent that induces mitogen‐activated protein kinase phosphatase have potential clinical utility for management of periodontal inflammation and alveolar bone.

Methods

Polyethylene glycol (PEG)‐polylactide (PLA) (PEG‐PLA) NPs were loaded with auranofin (ARN), an antirheumatic drug, to induce mitogen‐activated protein kinase phosphatase (MKP)‐1 expression in vitro and in vivo. Release kinetics of ARN from NPs was performed by high performance liquid chromatography (HPLC). Fluorescent‐labeled NPs were used to show uptake into macrophages by flow cytometry. Real‐time quantitative polymerase chain reaction (qPCR) was used to determine dual specificity protein phosphatase (Dusp)‐1 mRNA induction by Auranofin‐loaded nanoparticles (ARN‐NPs) and viability of ARN‐NPs was determined by colorimetric in vitro assays. Functional in vitro assays were used to measure functional MKP‐1 induction and preclinical models using Aggregatibacter actinomycetemcomitans lipopolysaccharide‐induced alveolar bone loss and microcomputed tomography was used to determine in vivo efficacy of functionalized ARN‐NPs.

Results

Data indicated that ARN‐NPs had reduced cytotoxicity compared with free ARN and Dusp1 mRNA and MKP‐1 activity was significantly increased by ARN‐NPs in vitro. Flow cytometry indicated rapid uptake into macrophages. Finally, significant bone loss reduction was observed with ARN‐NPs compared with control NPs in vivo using an lipopolysaccharide‐induced rat model of periodontitis.

Conclusion

Results from these studies suggest that developing NPs functionalized with ARN have anti‐inflammatory activities and may be a novel adjuvant therapeutic strategy to significantly improve periodontitis therapy and outcomes.
Systemic Concocting of Cross‐Linked Enzyme Aggregates of Candida antarctica Lipase B (Novozyme 435) for the Biomanufacturing of Rhamnolipids
Authors: Rathankumar Abiram Karanam , SaiLavanyaa Sundar , Saikia Kongkona , Gururajan Anusha , Sivanesan Subramanian , Gosselin Mathilde , Vaidyanathan Vinoth Kumar , Cabana Hubert
Published: February 2019

In the present study, Candida antarctica lipase B was immobilized on amine‐functionalized silica microspheres as cross‐linked enzyme aggregates (CLEA) and utilized for the biomanufacturing of rhamnolipids (RL). Lipase CLEA synthesized under optimized conditions of 2.0:1.0 by volume of silica microsphere/enzyme concentration, a 1.0:2.5 (v/v) ratio of enzyme/2‐propanol, 7 mM glutaraldehyde concentration, when incubated at pH 9.0 and 40 °C, for a cross‐linking time of 30 min were observed to exhibit superior biocatalytic properties and a maximum enzyme load of 770 U g−1. Lipase CLEA exhibited enhanced pH stability in acidic and alkaline media and increased temperature resistance as compared to free lipase. Both free and CLEA lipases were used to synthesize RL in different solvent systems. After 12 h, from initiation of the esterification, the degree of esterification (molar conversion yield) reached 46% and 71% in the batch mode. 1H and 13C nuclear magnetic resonance (NMR) and high‐performance liquid chromatographic (HPLC) analysis confirm RL production by CLEA lipase. The CLEA showed greater confrontation to enzyme‐mediated bioprocess approach as compared to its soluble counterpart and exhibited excellent RL production and catalytic activity even after its tenth successive reuse.
A practicable strategy for enrichment and separation of four minor flavonoids including two isomers from barley seedlings by macroporous resin column chromatography, medium‐pressure LC, and high‐speed countercurrent chromatography
Authors: Wang Nana , Chen Tao , Yang Xue , Shen Cheng , Li Hongmei , Wang Shuo , Zhao Jingyang , Chen Jilin , Chen Zhi , Li Yulin
Published: February 2019

Separation of minor compounds especially with similar polarities and structures from complex samples is a challenging work. In the present study, an efficient method was successfully established by macroporous resin column chromatography, medium‐pressure liquid chromatography, and high‐speed countercurrent chromatography for separation of four minor flavonoids from barley seedlings. Macroporous resin column chromatography and medium‐pressure liquid chromatography were used for enrichment of these four flavonoids. High‐pressure liquid chromatography analysis showed the total content of these four flavonoids increased from 2.2% in the crude extract to 95.3% in the medium‐pressure liquid chromatography fraction. It was indicated that the combination of macroporous resin column chromatography and medium‐pressure liquid chromatography could be a practicable strategy for enrichment of minor compounds from complex sample. Then, high‐speed countercurrent chromatography was employed for separation of these four flavonoids using ethyl acetate/n‐butanol/water (0.1% glacial acetic acid) (4:1:5, v/v/v) as solvent system. As a result, four flavonoids including two isomers with purities higher than 98% were obtained. Interestingly, two flavonoids existing in one high‐pressure liquid chromatography peak were also successfully separated. All these indicated high‐speed countercurrent chromatography had great potential for separation of compounds with similar structures and polarities. This study provides a reference for efficient enrichment and separation of minor compounds from complex sample.
Expression of trophic factors receptors during reinnervation after recurrent laryngeal nerve injury
Authors: Hernandez‐Morato Ignacio , Tian Likun , Montalbano Michael , Pitman Michael J.
Published: February 2019

Objective

An injury of the recurrent laryngeal nerve (RLN) triggers axonal regeneration but results in a poor functional recovery. Netrin‐1 and glial cell‐derived neurotrophic factor (GDNF) expression are up‐regulated in laryngeal muscles during RLN regeneration, but the role of their receptors produced in the nucleus ambiguus is unknown. The aim of this work was to determine the timing of the production of Netrin‐1 and GDNF receptors during RLN regeneration and correlate this with the previously identified timing of up‐regulation of their trophic factors in the laryngeal muscles.

Study Design

Laboratory experiment with rat model.

Methods

The right RLN was transected and dextran amine tracer applied. At 7, 14, and 21 days postinjury (DPI), brainstems were removed and harvested. Immunostaining was performed for Netrin‐1 (deleted in colorectal carcinoma [DCC], UNC5A) and GDNF receptors (rearranged during transfection [Ret], glycosylphosphatidylinositol‐linked cell surface receptors [GFRα1, GFRα2, GFRα3]). The timing and type of receptor production relative to injury as well as their position in the nucleus ambiguus was analyzed.

Results

Netrin‐1 UNC5A receptors were minimal in the nucleus ambiguus during RLN regeneration. DCC, the receptor that plays an attract role, was immunopositive from 7 to 21 DPI. All GDNF receptors, except GFRα2, were clearly positive from 7 to 14 DPI. No differences of production were observed according to the position of the motor neurons in the nucleus ambiguus.

Conclusion

An injury of the RLN leads to a higher production of Netrin‐1 DCC and GDNF receptors in the nucleus ambiguus. The timing of receptor production is similar to up‐regulation of their trophic factors in the laryngeal muscles.

Level of Evidence

NA.Laryngoscope, 129:2537–2542, 2019
The impact of repetitive hyperbaric exposure during SCUBA diving on cochlear implants
Authors: Hintze Justin M. , Geyer Lina , Fitzgerald Conall W. , Simoes Franklin Cristina , Glynn Fergal , Viani Laura , Walshe Peter
Published: February 2019

Objectives/Hypothesis

Complications during or after cochlear implantation are relatively rare. They occur more frequently in patients who partake in activities that can potentially lead to local trauma. No formal recommendations exist for participation in self‐contained underwater breathing apparatus (SCUBA) activities. We describe three patients with a combined five cochlear implants and extensive diving experience, the largest case series to date, and highlight some of the difficulties faced. We also review the literature on previously described SCUBA‐diving patients with cochlear implants.

Study Design

Retrospective case series and literature review.

Methods

A review of the known SCUBA divers in the National Hearing Implant and Research Centre in Ireland was conducted, and a review of the literature was carried out using PubMed and Google Scholar.

Results

Of the three SCUBA divers with cochlear implants, two required reimplantation, the first due to nonauditory stimulation, and the second due to extrusion of the electrode through the tympanic membrane following repetitive SCUBA dives. The third patient remains without complications after 80 dives.

Conclusions

Patients with cochlear implants can have complications relating to the implant itself, with device failure a theoretical risk. The cochleostomy can lead to perilymphatic extravasation, as well as inner ear barotrauma, decompression sickness, and formation of air bubbles along the electrode. A combination of deafness, vestibulopathy with abrupt perilymph leak, and loss of proprioception can lead to disorientation and blue dome syndrome. Based on our experience with cochlear implants in SCUBA divers, along with those reported in the literature, we recommend caution in patients with cochlear implants who SCUBA dive regularly and strict adherence to the recommended safety limits.

Level of Evidence: 4 129:2760–2764, 2019
Vulnerability assessment of the global water erosion tendency: Vegetation greening can partly offset increasing rainfall stress
Authors: Liu Yanxu , Fu Bojie , Liu Yue , Zhao Wenwu , Wang Shuai
Published: February 2019

Global water erosion is a grave threat to the sustainability of agriculture. Regional climate change may aggravate the threat of erosion, whereas global vegetation greening (an increasing trend in vegetation cover) may act as a mitigation to the threat. On the basis of the Revised Universal Soil Loss Equation, we assessed the vulnerability of the global water erosion during 1982–2015. A contribution index was built to describe the influences of rainfall erosivity and cover management on global water erosion vulnerability changes during 1982–2015. The research objective was to explore the spatial pattern of global water erosion vulnerability change in recent decades and to identify the factor that has contributed most to the vulnerability change, and three main results were obtained. (a) The global water erosion vulnerability increased over 51% of the surface during 1982–2015, and the surface with significant decreasing trends only accounted for 12% of the middle and highly sensitive areas. (b) Rainfall erosivity contributed more than cover management for absolute value except in the Amazon, Congo Basin, and Southeast Asia, whereas the contribution of cover management was increasing. (c) Vegetation greening can partly offset the stress caused by climate change. The global water erosion vulnerability decreased more than increased in sensitive area. Consequently, enhancing the vegetation growth in the highly sensitive water erosion region could reduce the erosion threat at large scale.
A Facile Strategy for Fabricating Tissue Engineering Scaffolds with Sophisticated Prevascularized Networks for Bulk Tissue Regeneration
Authors: Liu Sui‐Hong , Zhang Hai‐Guang , Li Shuai , Sun Cheng‐Yan , Hu Qing‐Xi
Published: February 2019

Despite the fact that the field of tissue engineering has had considerable advances over the past two decades, a series of unsolved problems still remain. Vascularization is one of the most important factors that greatly influence the function and size of the engineered scaffolds, which limits the clinical applications. In this work, a facile extracted molding method is presented for fabricating bulk tissue scaffolds with spatial networks. Briefly, the branched templates are designed, coated with paraffin on the surface, immersed into the mixture of microbial transglutaminase and gelatin, and extracted from fully enzymatic cross‐linking gelatin. The perfusion test is done and the mechanical properties of the scaffolds are investigated. Furthermore, in vitro and in vivo experiments demonstrate the nontoxicity and biocompatibility of the materials and fabrication process. Thus, this approach has great potential to overcome the challenge of rapid oxygen and nutrient delivery to engineered vascularized tissues implanted in vivo, opening the way to clinical applications.
Preparation and Characterization of Temperature‐Sensitive Poly(Styrene‐Butadiene‐Styrene)/Poly(N‐Isopropylacrylamide) Hydrogel Elastomer with Interpenetrating Polymeric Networks
Authors: Liu Xifei , Zhang Aimin , Su Gehong , Xie Haisheng , Shi Xiaotao , Li Lin
Published: February 2019

A poly(styrene‐butadiene‐styrene)/poly(N‐isopropylacrylamide) (SBS/PNIPAM) hydrogel elastomer with interpenetrating polymeric network structure is prepared by using solution free radical polymerization in benzene/tetrahydrofuran solvent mixture. The characterizations of hydrogel elastomers are investigated by Fourier transform infrared spectroscopy, scanning electron microscope, rheology, equilibrium swelling studies, and oscillatory swelling study. Results show that these hydrogel elastomers exhibit a temperature‐sensitivity inherited from PNIPAM component at the temperature around 30 °C. Besides, change with tetrahydrofuran to different proportion in solvent mixtures, constituent, and properties as gel content, swelling capacity, mechanical strength and volume phase transition degree are affected deeply.
Organic Molecule‐Driven Polymeric Actuators
Authors: Lin Huijuan , Zhang Suyun , Xiao Yan , Zhang Chenjun , Zhu Jixin , Dunlop John W. C. , Yuan Jiayin
Published: February 2019

Inspired by the motions of plant tissues in response to external stimuli, significant attention has been devoted to the development of actuating polymeric materials. In particular, polymeric actuators driven by organic molecules have been designed due to their combined superiorities of tunable functional monomers, designable chemical structures, and variable structural anisotropy. Here, the recent progress is summarized in terms of material synthesis, structure design, polymer–solvent interaction, and actuating performance. In addition, various possibilities for practical applications, including the ability to sense chemical vapors and solvent isomers, and future directions to satisfy the requirement of sensing and smart systems are also highlighted.
C‐terminal regulatory domain of the ε subunit of FoF1 ATP synthase enhances the ATP‐dependent H+ pumping that is involved in the maintenance of cellular membrane potential in Bacillus subtilis
Authors: Akanuma Genki , Tagana Tomoaki , Sawada Maho , Suzuki Shota , Shimada Tomohiro , Tanaka Kan , Kawamura Fujio , Kato‐Yamada Yasuyuki
Published: February 2019

The ε subunit of FoF1‐ATPase/synthase (FoF1) plays a crucial role in regulating FoF1 activity. To understand the physiological significance of the ε subunit‐mediated regulation of FoF1 in Bacillus subtilis, we constructed and characterized a mutant harboring a deletion in the C‐terminal regulatory domain of the ε subunit (ε∆C). Analyses using inverted membrane vesicles revealed that the ε∆C mutation decreased ATPase activity and the ATP‐dependent H+‐pumping activity of FoF1. To enhance the effects of ε∆C mutation, this mutation was introduced into a ∆rrn8 strain harboring only two of the 10 rrn (rRNA) operons (∆rrn8 ε∆C mutant strain). Interestingly, growth of the ∆rrn8 ε∆C mutant stalled at late‐exponential phase. During the stalled growth phase, the membrane potential of the ∆rrn8 ε∆C mutant cells was significantly reduced, which led to a decrease in the cellular level of 70S ribosomes. The growth stalling was suppressed by adding glucose into the culture medium. Our findings suggest that the C‐terminal region of the ε subunit is important for alleviating the temporal reduction in the membrane potential, by enhancing the ATP‐dependent H+‐pumping activity of FoF1.
Algicidal bacteria trigger contrasting responses in model diatom communities of different composition
Authors: Bigalke Arite , Pohnert Georg
Published: February 2019

Algicidal bacteria are important players regulating the dynamic changes of plankton assemblages. Most studies on these bacteria have focused on the effect on single algal species in simple incubation experiments. Considering the complexity of species assemblages in the natural plankton, such incubations represent an oversimplification and do not allow making further reaching conclusions on ecological interactions. Here, we describe a series of co‐incubation experiments with different level of complexity to elucidate the effect of the algicidal bacterium Kordia algicida on mixed cultures of a resistant and a susceptible diatom. The growth of the resistant diatom Chaetoceros didymus is nearly unaffected by K. algicida in monoculture, while cells of the susceptible diatom Skeletonema costatum are lysed within few hours. Growth of C. didymus is inhibited if mixed cultures of the two diatoms are infected with the bacterium. Incubations with filtrates of the infected cultures show that the effects are chemically mediated. In non‐contact co‐culturing we show that low concentrations of the lysed algae support the growth of C. didymus, while higher concentrations trigger population decline. Complex cascading effects of algicidal bacteria have thus to be taken into account if their ecological role is concerned.
Blocking gate resonator rasorber surface brings wide band electromagnetic absorption performance approaching theoretical limit
Authors: Yuan Xujin , Xu Yuannan , Chen Mingji , Cheng Xiaodong , Fang Daining
Published: February 2019

In wide band electromagnetic absorbers, absorption in high and low frequency domain usually influence each other. Rasorber structure with blocking gate resonator (BGR) sub‐wavelength unit surface is proposed and applied in electromagnetic wave absorber to resolve this problem. The absorber has −10 dB low‐reflectivity performance operating in bandwidth ratio 161.2% and approaches Rozanov's theory limit in low frequency. BGR unit surface also generate a 2‐step design method for multi‐layer absorber structure. Rasorber BGR unit surface helps to enhance low frequency absorption with limited thickness while maintain absorption in relative higher wide frequency range by impedance matching at low frequency. Sample fabrication and experiment measurement basically testify the numerical speculations.
Broad‐band H‐spaced head‐shaped slot with SIW‐based antenna for 60 GHz wireless communication applications
Authors: Mungaru Nanda Kumar , Shanmuganantham Thangavelu
Published: February 2019

In this article, a compact SIW‐based H‐spaced head‐shaped slot antenna is proposed, and slot is etched into the top, proposed design printed by RT‐Duriod 5880 substrate (εr = 2.2), which is accountable for achieving millimeter‐wave wireless applications, small size, and broadband operation. The SIW‐based slot antenna with a compacted dimension of 14 × 8 × 0.381 mm3 is fabricated and tested. The testing results show that the design proposed, having occupied frequency range from 58.5 to 61.72 GHz, respectively, covers V‐band (millimeter wireless communications applications). The testing and simulation result bandwidth range of a proposed design is 4.22 and 4.19 GHz. It has fine radiation characteristics for both E‐field and H‐field in all the preferred operational bands and generates superior performances compared to the existing design antenna in the reviews.
Self‐generating Brillouin fiber laser using highly nonlinear hafnium bismuth erbium‐doped fiber
Authors: Ahmad Aminah , Cheng Xiau San , Paul Mukul Chandran , Dhar Anirban , Das Shyamal , Ahmad Harith , Harun Sulaiman Wadi
Published: February 2019

A compact Brillouin fiber laser (BFL) utilizing a newly developed hafnium bismuth erbium‐doped fiber (HB‐EDF), which functions as both the Brillouin and linear gain media, is realized in the absence of Brillouin pump. It is achieved by the self‐Brillouin generation from a 0.2 m length of HB‐EDF with high nonlinearity in a laser cavity. The self‐generating BFL was obtained in both ring and linear laser cavities. Compared to the ring cavity, the BFL in the linear cavity produced more Brillouin stokes at a lower pump threshold. In the experiment, an eight‐line comb with average spacing of 0.087 nm was generated at the HB‐EDF pump power of 75.27 mW. This compact BFL has total cavity length of less than 0.5 m, and thus, this is the shortest gain medium reported for Brillouin erbium fiber laser generation without using any Brillouin pump.
Enhancement of the performance of the Cu2Se band filters via Yb nanosandwiching
Authors: Khusayfan Najla M. , Qasrawi A. F. , Khanfar Hazem K.
Published: February 2019

In this article, we report the experimental and theoretical modeling on the band pass filters that are made of two thin film layers of Cu2Se coated onto aluminum substrates and nanosandwiched with 50 nm ytterbium layers. The nanosandwiching of Yb between two layers of Cu2Se is found to decrease the lattice constant, the defect density, and the strain and increase the grain size in the Cu2Se. Electrically, it is observed that, Al/Cu2Se/Al structure exhibits wave trap characteristics with notch frequency of 1.31 GHz. The Yb‐layers improved the performance of the band pass filters by increasing the amplitude of the reflection coefficients, increasing the return loss values and decreasing the voltage standing wave ratios. The calculated conduction and wave trapping parameters nominate the Yb‐nanosandwiched Cu2Se films for use in communication technology as they exhibit negative capacitance effect and narrow band pass range.
Circular sectoral waveguide TM01 to TE11 mode converter
Authors: Kumar Vikram , Dwivedi Smrity , Jain Pradip K.
Published: February 2019

A high power microwave (HPM) TM01 to TE11 mode converter using circular sectoral waveguide (CSWG) is analyzed in this article. The design is simulated and validated by the measurements. The conversion efficiency is more than 90% over the frequency range 2.97‐3.02 GHz, Along with more than 99% of the input power is radiated at 3 GHz. The proposed all metal CSWG mode converter is of low weight, linear in design and HPM sustainable, having high return loss and good conversion efficiency.
23.5‐30 GHz gallium nitride on silicon power amplifier MMIC with 7.6‐12.4 W saturation output power
Authors: Tong Xiaodong , Zhang Shiyong , Zheng Penghui , Xu Jianxing , Wang Rong
Published: February 2019

A 23.5‐30 GHz power amplifier (PA) using 0.1‐μm gallium nitride (GaN) on silicon (Si) microwave monolithic integrated circuit (MMIC) process is presented in this work. The area of this PA MMIC is 3.7 mm × 3.2 mm (11.8 mm2). The measured linear gain is 16.4‐19.4 dB with input/output return loss over 10 dB. The measured saturation output power (Psat) is 7.6‐12.4 W under pulsed working condition. The drain voltage is 12 V and the total drain current is 2.6 A, which induce a power added efficiency (PAE) of 26%‐37%. The reported GaN on Si (GaN/Si) PA has high power, high efficiency and low cost. It is more suitable for massive commercial application compared with the traditional GaN on silicon‐carbon (GaN/SiC) PA. As we know, there has been no high output power GaN/Si PA as high as 10 W level reported in the 20‐30 GHz frequency region.
Miniaturized dual‐band branch‐line coupler with enhanced bandwidth
Authors: Bekasiewicz Adrian
Published: February 2019

In this letter, a miniaturized hybrid dual‐band branch‐line coupler (BLC) with enhanced fractional bandwidths is proposed. Compact size and bandwidth enhancement are obtained using meandered transmission line sections with broken symmetry between cross‐coupling branches. The circuit is designed at a low numerical cost using surrogate‐assisted techniques. The optimized design features small size of only 0.25 λ
g × 0.19 λ
g (28% miniaturization with respect to conventional single‐band structure), as well as fractional bandwidths of 16% and 9% for 2.5 GHz and 5.4 GHz center frequencies, respectively. The proposed structure is compared against state‐of‐the‐art dual‐band couplers and validated experimentally.
Automatic multiorgan segmentation in thorax CT images using U‐net‐GAN
Authors: Dong Xue , Lei Yang , Wang Tonghe , Thomas Matthew , Tang Leonardo , Curran Walter J. , Liu Tian , Yang Xiaofeng
Published: February 2019

Purpose

Accurate and timely organs‐at‐risk (OARs) segmentation is key to efficient and high‐quality radiation therapy planning. The purpose of this work is to develop a deep learning‐based method to automatically segment multiple thoracic OARs on chest computed tomography (CT) for radiotherapy treatment planning.

Methods

We propose an adversarial training strategy to train deep neural networks for the segmentation of multiple organs on thoracic CT images. The proposed design of adversarial networks, called U‐Net‐generative adversarial network (U‐Net‐GAN), jointly trains a set of U‐Nets as generators and fully convolutional networks (FCNs) as discriminators. Specifically, the generator, composed of U‐Net, produces an image segmentation map of multiple organs by an end‐to‐end mapping learned from CT image to multiorgan‐segmented OARs. The discriminator, structured as an FCN, discriminates between the ground truth and segmented OARs produced by the generator. The generator and discriminator compete against each other in an adversarial learning process to produce the optimal segmentation map of multiple organs. Our segmentation results were compared with manually segmented OARs (ground truth) for quantitative evaluations in geometric difference, as well as dosimetric performance by investigating the dose‐volume histogram in 20 stereotactic body radiation therapy (SBRT) lung plans.

Results

This segmentation technique was applied to delineate the left and right lungs, spinal cord, esophagus, and heart using 35 patients’ chest CTs. The averaged dice similarity coefficient for the above five OARs are 0.97, 0.97, 0.90, 0.75, and 0.87, respectively. The mean surface distance of the five OARs obtained with proposed method ranges between 0.4 and 1.5 mm on average among all 35 patients. The mean dose differences on the 20 SBRT lung plans are −0.001 to 0.155 Gy for the five OARs.

Conclusion

We have investigated a novel deep learning‐based approach with a GAN strategy to segment multiple OARs in the thorax using chest CT images and demonstrated its feasibility and reliability. This is a potentially valuable method for improving the efficiency of chest radiotherapy treatment planning.
In air and in vivo measurement of the leaf open time in tomotherapy using the on‐board detector pulse‐by‐pulse data
Authors: Schopfer Mathieu , Bochud François O. , Bourhis Jean , Moeckli Raphaël
Published: February 2019

Purpose

We developed an algorithm to measure the leaf open times (LOT) from the on‐board detector (OBD) pulse‐by‐pulse data in tomotherapy. We assessed the feasibility of measuring the LOTs in dynamic jaw mode and validated the algorithm on machine QA and clinical data. Knowledge of the actual LOTs is a basis toward calculating the delivered dose and performing efficient phantom‐less delivery quality assurance (DQA) controls of the multileaf collimator (MLC). In tomotherapy, the quality of the delivered dose depends on the correct performance of the MLC, hence on the accuracy of the LOTs.

Materials and methods

In the detector signal, the period of time during which a leaf is open corresponds to a high intensity region. The algorithm described here locally normalizes the detector signal and measures the FWHM of the high intensity regions.

The Daily QA module of the TomoTherapy Quality Assurance (TQA) tool measures LOT errors. The Daily QA detector data were collected during 9 days on two tomotherapy units. The errors yielded by the method were compared to these reported by the Daily QA module.

In addition, clinical data were acquired on the two units (25 plans in total), in air without attenuation material in the beam path and in vivo during a treatment fraction. The study included plans with fields of all existing sizes (1.05, 2.51, 5.05 cm). The collimator jaws were in dynamic mode (TomoEDGETM). The feasibility of measuring the LOTs was assessed with respect to the jaw aperture.

Results

The mean discrepancy between LOTs measured by the algorithm and those measured by TQA was of 0 ms, with a standard deviation of 0.3 ms. The LOT measured by the method had thus an uncertainty of 1 ms with a confidence level of 99%.

In 5.05 cm dynamic jaw procedures, the detector is in the beam umbra at the beginning and at the end of the delivery. In such procedures, the algorithm could not measure the LOTs at jaw apertures between 7 and maximum 12.4 mm. Otherwise, no measurement error due to the jaw movement was observed. No LOT measurement difference between air and in vivo data was observed either.

Conclusion

The method we propose is reliable. It can equivalently measure the LOTs from data acquired in air or in vivo. It handles fully the static procedures and the 2.51 cm dynamic procedures. It handles partially the 5.05 cm dynamic procedures. The limitation was evaluated with respect to the jaw aperture.
Experienced barriers in shared decision‐making behaviour of orthopaedic surgery residents compared with orthopaedic surgeons
Authors: Bossen Jeroen K.J. , van der Weijden Trudy , Driessen Erik W. , Heyligers Ide C.
Published: February 2019

Introduction

In shared decision‐making (SDM), physicians encourage the patient to participate in the care process. The theory of planned behaviour describes that behaviour is dependent on intention. In its turn, intention is explained by attitude, subjective norm and perceived behavioural control. In orthopaedics, little is known about current SDM behaviour and how to promote it.The aim of the present study was to gain insight into the SDM behaviour of orthopaedic residents and supervisors by measuring levels of intention, attitudes, subjective norms and perceived behavioural control. Furthermore, we aimed to determine the predictors of intention for SDM.

Methods

A questionnaire survey study was conducted among orthopaedic surgeons and residents working in the care of hip and knee osteoarthritis, to determine their intentions, attitudes, subjective norms and perceived behavioural control regarding SDM.

Results

Of the 385 physicians approached, 71 residents and 64 orthopaedic surgeons participated. Residents and the supervisors alike had positive intentions regarding SDM. Intention for SDM behaviour was explained by attitude, subjective norm and perceived behavioural control, with perceived behavioural control having the strongest association. In residents, the intention to engage in SDM was more hampered by a lower level of perceived behavioural control than in surgeons.

Conclusions

Physicians are willing to perform SDM and consider SDM as favourable in the orthopaedic clinic. The implementation of SDM is mainly hampered by experienced barriers that they cannot control. These findings underline the importance of incorporating SDM in the curriculum of postgraduates. Possibilities for efficient SDM implementation should be explored, to overcome perceived barriers.
Reflections on the implementation of the provisional best practices guidelines for the evaluation of bulbar dysfunction in ALS
Authors: Gwathmey Kelly G. , Berggren Kiera N.
Published: February 2019

See article on pages 531–536 in this issue.
Sensory modulation of fasciculation discharge frequency
Authors: de Carvalho Mamede , Turkman Antonia , Swash Michael
Published: February 2019

Introduction: Fasciculations are a marker for the diagnosis of amyotrophic lateral sclerosis (ALS) and reflect increased lower motor neuron (LMN) excitability. Methods: We investigated modulation of fasciculation frequency in the first dorsal interosseous (FDI) muscle of the right hand following peripheral sensory nerve electrical stimulation, and vibration over the muscle‐tendon region (50 and 100 Hz), in patients with ALS, spinal muscular atrophy, and benign fasciculation syndrome. FDI muscles of ALS patients were classified by the presence or absence of neurogenic changes on needle electromyography. Results: Both sensory nerve electrical stimulation and vibration significantly increased the frequency of fasciculations in neurogenic FDI muscles of ALS patients, but not in the remaining groups. Discussion: Our results favour increased excitability of LMNs when affected by the disease process in ALS. We found that some fasciculations originating in these neurons in ALS are susceptible to modulation by sensory input. Muscle Nerve 59:688–693, 2019
Fast quantitative susceptibility reconstruction via total field inversion with improved weighted L0 norm approximation
Authors: Zhang Li , Chen Xi , Lin Jianzhong , Ding Xinghao , Bao Lijun , Cai Congbo , Li Jing , Chen Zhong , Cai Shuhui
Published: February 2019

Quantitative susceptibility mapping (QSM) is a meaningful MRI technique owing to its unique relation to actual physical tissue magnetic properties. The reconstruction of QSM is usually decomposed into three sub‐problems, which are solved independently. However, this decomposition does not conform to the causes of the problems, and may cause discontinuity of parameters and error accumulation. In this paper, a fast reconstruction method named fast TFI based on total field inversion was proposed. It can accelerate the total field inversion by using a specially selected preconditioner and advanced solution of the weighted L0 regularization. Due to the employment of an effective model, the proposed method can efficiently reconstruct the QSM of brains with lesions, where other methods may encounter problems. Experimental results from simulation and in vivo data verified that the new method has better reconstruction accuracy, faster convergence ability and excellent robustness, which may promote clinical application of QSM.
Continuous prospectively navigated multi‐echo GRE for improved BOLD imaging of the kidneys
Authors: Morrell Glen Robert , Jeong Eun‐Kee , Shi Xianfeng , Zhang Lei , Lee Vivian Shu‐Ching
Published: February 2019

The objective of this study is to develop improved methods for renal blood oxygenation level dependent (BOLD) imaging. T2* mapping of the kidneys, or renal BOLD imaging, may depict renal oxygen levels and may be valuable as a noninvasive means of following the progression of renal disease. Current renal BOLD data is limited by imaging in a single breath hold, which results in low resolution and low signal‐to‐noise ratio (SNR). We compare a new free‐breathing renal BOLD method with conventional breath‐hold BOLD (BH‐BOLD).

A multi‐echo GRE sequence with continuous prospective respiratory navigation and real‐time feedback was developed that allows high resolution and high SNR renal BOLD imaging with constant sequence repetition time (TR) during free‐breathing BOLD (FB‐BOLD). The sequence was evaluated in 10 normal volunteers and compared with conventional BH‐BOLD. Scan time for the FB‐BOLD sequence was approximately three minutes, compared with 15 seconds for the BH‐BOLD sequence. SNR of source images and residual error of T2* fitting were compared between the two methods.

The FB‐BOLD sequence produced motion‐free T2* maps of the kidneys with SNR 1.9 times higher than BH‐BOLD images. Residual error of T2* fitting was consistently lower in the right kidney with FB‐BOLD (30% less than BH‐BOLD) but higher in the left kidney (80% more than BH‐BOLD), likely related to placement of the navigator on the right hemidiaphragm.

A free‐breathing prospectively navigated renal BOLD sequence allows flexible tradeoff between scan time, resolution, and SNR.