bluuebunny/crossref_metadata_2025_split huggingface dataset:
Active microbial biofilms in deep poor porous continental subsurface rocks
Authors: Escudero Cristina , Vera Mario , Oggerin Monike , Amils Ricardo 
Published: January 2018

AbstractDeep continental subsurface is defined as oligotrophic environments where microorganisms present a very low metabolic rate. To date, due to the energetic cost of production and maintenance of biofilms, their existence has not been considered in poor porous subsurface rocks. We applied fluorescence in situ hybridization techniques and confocal laser scanning microscopy in samples from a continental deep drilling project to analyze the prokaryotic diversity and distribution and the possible existence of biofilms. Our results show the existence of natural microbial biofilms at all checked depths of the Iberian Pyrite Belt (IPB) subsurface and the co-occurrence of bacteria and archaea in this environment. This observation suggests that multi-species biofilms may be a common and widespread lifestyle in subsurface environments.
Mitochondrial biogenesis and metabolic hyperactivation limits the application of MTT assay in the estimation of radiation induced growth inhibition
Authors: Rai Yogesh , Pathak Richa , Kumari Neeraj , Sah Dhananjay Kumar , Pandey Sanjay , Kalra Namita , Soni Ravi , Dwarakanath B. S. , Bhatt Anant Narayan 
Published: January 2018

AbstractMetabolic viability based high throughput assays like MTT and MTS are widely used in assessing the cell viability. However, alteration in both mitochondrial content and metabolism can influence the metabolic viability of cells and radiation is a potential mitochondrial biogenesis inducer. Therefore, we tested if MTT assay is a true measure of radiation induced cell death in widely used cell lines. Radiation induced cellular growth inhibition was performed by enumerating cell numbers and metabolic viability using MTT assay at 24 and 48 hours (hrs) after exposure. The extent of radiation induced reduction in cell number was found to be larger than the decrease in MTT reduction in all the cell lines tested. We demonstrated that radiation induces PGC-1α and TFAM to stimulate mitochondrial biogenesis leading to increased levels of SDH-A and enhanced metabolic viability. Radiation induced disturbance in calcium (Ca2+) homeostasis also plays a crucial role by making the mitochondria hyperactive. These findings suggest that radiation induces mitochondrial biogenesis and hyperactivation leading to increased metabolic viability and MTT reduction. Therefore, conclusions drawn on radiation induced growth inhibition based on metabolic viability assays are likely to be erroneous as it may not correlate with growth inhibition and/or loss of clonogenic survival.
New 2-Aryl-9-methyl-β-carbolinium salts as Potential Acetylcholinesterase Inhibitor agents: Synthesis, Bioactivity and Structure–Activity Relationship
Authors: Zhou Bohang , Zhang Bingyu , Li Xingqiang , Liu Xiuxiu , Li Hui , Li Ding , Cui Zhiming , Geng Huiling , Zhou Le 
Published: January 2018

AbstractA series of 2-aryl-9-methyl-β-carbolinium bromides (B) were synthesized and explored for anti-acetylcholinesterase (AChE) activities in vitro, action mechanism and structure-activity relationship. All the compounds B along with their respective 3,4-dihydro intermediates (A) presented anti-AChE activity at 10 μM. Thirteen compounds B showed the excellent activity with IC50 values of 0.11–0.76 μM and high selectivity toward AChE relative to butyrylcholinesterase (BChE), superior to galantamine (IC50 = 0.79 μM), a selective AChE inhibitor drug. Kinetic analysis showed that the action mechanisms of both compounds B and A are a competitive inhibition model. Structure-activity relationship analyses showed that the C = N+ moiety is a determinant for the activity. Substituents at 6, 7 or 4′ site, the indole-N-alkyl and the aromatization of the C-ring can significantly improve the activity. Molecular docking studies showed that the compounds could combine with the active site of AChE by the π-π or cation-π action between the carboline ring and the phenyl rings of the residues, and the β-carboline moiety is embedded in a cavity surrounded by four aromatic residues of Trp86, Tyr337, Trp439 and Tyr449. The present results strongly suggest that the para-position of the D-ring should be a preferred modification site for further structural optimization design. Thus, 2-aryl-9-methyl-β-carboliniums emerged as novel and promising tool compounds for the development of new AChE inhibitor agents.
Antimicrobial activity of Ti-ZrN/Ag coatings for use in biomaterial applications
Authors: Slate Anthony J. , Wickens David J. , El Mohtadi Mohamed , Dempsey-Hibbert Nina , West Glen , Banks Craig E. , Whitehead Kathryn A. 
Published: January 2018

AbstractSeverely broken bones often require external bone fixation pins to provide support but they can become infected. In order to reduce such infections, novel solutions are required. Titanium zirconium nitride (Ti-ZrN) and Ti-ZrN silver (Ti-ZrN/Ag) coatings were deposited onto stainless steel. Surface microtopography demonstrated that on the silver containing surfaces, S
a
and S
v
values demonstrated similar trends whilst the R
a
, average height and RMS value and S
p
values increased with increasing silver concentration. On the Ti-ZrN/Ag coatings, surface hydrophobicity followed the same trend as the S
a
and S
v
values. An increase in dead Staphylococcus aureus and Staphylococcus epidermidis cells was observed on the coatings with a higher silver concentration. Using CTC staining, a significant increase in S. aureus respiration on the silver containing surfaces was observed in comparison to the stainless steel control whilst against S. epidermidis, no significant difference in viable cells was observed across the surfaces. Cytotoxicity testing revealed that the TiZrN coatings, both with and without varying silver concentrations, did not possess a detrimental effect to a human monocyte cell line U937. This work demonstrated that such coatings have the potential to reduce the viability of bacteria that result in pin tract infections.
Use of whole genome sequencing to investigate an increase in Neisseria gonorrhoeae infection among women in urban areas of Australia
Authors: Buckley Cameron , Forde Brian M. , Trembizki Ella , Lahra Monica M. , Beatson Scott A. , Whiley David M. 
Published: January 2018

AbstractIncreasing rates of gonorrhoea have been observed among women within the Australian state of New South Wales. Here, we applied whole genome sequencing (WGS) to better understand the associated networks and transmission dynamics. Ninety-four isolates of a particular N. gonorrhoeae genotype (G122) associated with women (years 2012 to 2014) underwent phylogenetic analysis using core single nucleotide polymorphisms. WGS data revealed five main clusters, all of which were heterogeneous in terms of patient age and site of infection. The relatively high cervical/vaginal infections in each cluster was indicative of transmission in the general heterosexual population, noting that there is typically high rates of condom use for vaginal sex among local commercial sex workers. WGS also enabled the identification of groups of individuals belonging to tighter transmission chains within clusters, and hence may present a new tool for targeting public health interventions. The enhanced resolution of WGS provides a ready means of confirming suspected changes in N. gonorrhoeae epidemiology, but also enables key features to be identified or new questions to be raised regarding the composition of the associated sexual networks.
Graphene-based nonvolatile terahertz switch with asymmetric electrodes
Authors: Li Yan , Yu Hui , Qiu Xinyu , Dai Tingge , Jiang Jianfei , Wang Gencheng , Zhang Qiang , Qin Yali , Yang Jianyi , Jiang Xiaoqing 
Published: January 2018

AbstractWe propose a nonvolatile terahertz (THz) switch which is able to perform the switching with transient stimulus. The device utilizes graphene as its floating-gate layer, which changes the transmissivity of THz signal by trapping the tunneling charges. The conventional top-down electrode configuration is replaced by a left-right electrode configuration, so THz signals could transmit through this device with the transmissivity being controlled by voltage pulses. The two electrodes are made of metals with different work functions. The resultant asymmetrical energy band structure ensures that both electrical programming and erasing are viable. With the aid of localized surface plasmon resonances in graphene ribbon arrays, the modulation depth is 89% provided that the Femi level of graphene is tuned between 0 and 0.2 eV by proper voltage pulses.
High diversity and abundance of cultivable tetracycline-resistant bacteria in soil following pig manure application
Authors: Kang Yijun , Li Qing , Yin Zhifeng , Shen Min , Zhao Haitao , Bai Yanchao , Mei Lijuan , Hu Jian 
Published: January 2018

AbstractBy performing a microcosm experiment mimicking fertilization, we assessed the dynamic distribution of tetracycline-resistant bacteria (TRB) and corresponding tetracycline resistance genes (TRGs) from pig manure (PM) to the fertilized soil, by culture-dependent methods and PCR detection. Cultivable TRB were most abundant in PM, followed by fertilized soil and unfertilized soil. By restriction fragment length polymorphism (RFLP) analysis, TRB were assigned to 29, 20, and 153 operational taxonomic units (OTUs) in PM, unfertilized soil, and fertilized soil, respectively. After identification, they were further grouped into 19, 12, and 62 species, showing an enhanced diversity of cultivable TRB in the soil following PM application. The proportions of potentially pathogenic TRB in fertilized soil decreased by 69.35% and 41.92% compared with PM and unfertilized soil. Bacillus cereus was likely widely distributed TRB under various environments, and Rhodococcus erythropolis and Acinetobacter sp. probably spread from PM to the soil via fertilization. Meanwhile, tetL was the most common efflux pump gene in both unfertilized and fertilized soils relative to PM; tetB(P) and tet36 were common in PM, whereas tetO was predominant in unfertilized and fertilized soil samples. Sequencing indicated that over 65% of randomly selected TRB in fertilized soil with acquired resistance derived from PM.
Multilocus Sequence Typing Reveals both Shared and Unique Genotypes of Cryptococcus neoformans in Jiangxi Province, China
Authors: Chen Yan-Hui , Yu Feng , Bian Ze-Yuan , Hong Jian-Ming , Zhang Nan , Zhong Qiao-Shi , Hang Ya-Ping , Xu Jianping , Hu Long-Hua 
Published: January 2018

AbstractCryptococcosis is a globally distributed infectious fungal disease. However, much remains unknown about its molecular epidemiology in many parts of the world. In this study, we analyzed 86 clinical Cryptococcus neoformans isolates from 14 regions in Jiangxi Province in south central China. Each isolate was from a different patient and 35 of the 86 (40.7%) patients were infected with HIV. All strains belonged to serotype A and mating type α (MATα). Genotyping based on DNA sequences at seven nuclear loci revealed eight sequence types (STs) among the 86 isolates, including two novel STs that have not been reported from other parts of the world. ST5 was the dominant genotype and our comparative analyses showed that these genotypes in Jiangxi likely originated by dispersal from other regions within and outside of China and/or mutations from another genotype within Jiangxi. Though none of the isolates was resistant to the five tested antifungal drugs (flucytosine, amphotericin B, fluconazole, itraconazole, and voriconazole), obvious differences in their minimum inhibitory concentrations were observed, even among isolates of the same ST. Our results suggest that continuous monitoring should be conducted to understand the changing dynamics of C. neoformans in this and other regions.
A Comparison of the Operative Techniques and the Postoperative Complications for Bone-Anchored Hearing Aid Implantation
Authors: Steehler Mark , Larner Sean , Mintz Joshua , Steehler Matthew , Lipman Sidney , Griffith Shane 
Published: January 2018

Introduction Bone anchored hearing aids (BAHA) represent a useful surgical option for patients with single sided deafness.
Objectives To compare multiple techniques for BAHA implantation regarding postoperative complications, operative time, and duration between the surgery and the first use of the BAHA.
Methods A retrospective study was conducted of all patients receiving implantation of a BAHA from August of 2008 to October of 2014. Data collected included: patient age, gender, side operated, abutment length, operative time, duration until first use of the BAHA, operative technique, and postoperative complications. The statistical analysis was performed using analysis of variance (ANOVA), Tukey pairwise comparison, chi-square, and paired t-test. Statistical significance was determined using a level of p < 0.05.
Results A total of 88 patients (43 female and 45 male) were included in the data analysis. A total of 80 complications were documented, and these complications were classified according to the Holgers criteria. A significant difference in the total postoperative complications existed between the six techniques used (ANOVA; p < 0.01). In addition, there was also a significant difference among the six techniques employed regarding the operative time (ANOVA; p < 0.01). The average time duration until fitting of the BAHA processor among the various techniques trended toward but did not reach statistical significance (ANOVA; p = 0.16).
Conclusions Significant differences in the operative outcomes exist among the various techniques for BAHA implantation. Based on the statistical analysis of our data, the BAHA Attract system (Cochlear Ltd., Sidney, Australia) requires greater operative time, but it is associated with less postoperative complications than percutaneous techniques and its processor may be fitted significantly sooner.
Extended Retrosigmoid Approach for Cerebellopontine Angle Meningiomas: Operative Technique and Results—A Series of 28 Patients
Authors: Pereira Celestino , Welling Leonardo , Gonçalves Mariangela , Zanon Nelci , Lynch Jose 
Published: January 2018

Background The purpose of this article is to describe our approach, surgical strategies, and results for resection of meningiomas located at cerebellopontine angle (CPA).
Methods We retrospectively identified 28 patients with CPA meningiomas operated by the extended retrosigmoid approach. This approach incorporates a generous mastoidectomy and the sigmoid sinus exposure.
Results The mean age was 33.8 years, with a follow-up of 12.5 years. Gross total removal (GTR) was achieved in 22 (78.5%) patients with low surgical mortality, acceptable morbidity, and recurrence rate of 7.1% (2 patients).
Conclusion The extended retrosigmoid approach enhances the exposure of the CPA and posterior fossa cisterns and increases the surgical angle of maneuverability. This approach provides adequate access even to extensive CPA meningiomas, enabling, in most of cases, GTR to be safe and effective. The extended retrosigmoid approach used in this group of patients is an alternative to more extensive cranial base approaches.
Ultra-Early Optic Nerve Decompression for the Resection of Anterior Clinoidal Meningioma
Authors: Oya Soichi , Matsui Toru 
Published: January 2018

AbstractImprovement in vision is one of the main goals of surgery for anterior clinoidal meningiomas with visual deficits. Early optic nerve decompression surgery has been advocated in previous studies to achieve the best visual outcome. Through this video, the authors describe their surgical techniques to decompress the optic nerve at the very early stage of surgery. A 35-year-old patient presented with subjective blurry vision in the right eye over the last 8 months. Magnetic resonance images showed a 3.2-cm meningioma arising at the right anterior clinoid. Preoperative ophthalmological test was within the normal range, but the patient wished to have surgical resection after a detailed discussion of benefits and risks related to surgical resection. The surgical strategy consisted of the right lateral subfrontal approach that includes a standard right frontotemporal craniotomy, extradural anterior clinoidectomy, and early optic nerve decompression prior to tumor resection. The tumor was divided into compartments defined by the arteries and resected. Simpson grade II resection was achieved without complications. The patient's symptoms disappeared. In anterior clinoidal meningiomas that cause visual deficits, the optic nerve is assumed very vulnerable to any further injuries related to the operative maneuver. Ultra-early optic nerve decompression can be performed in anterior clinoidal meningiomas regardless of their size by extradural unroofing of the optic canal and sectioning of the optic canal sheath, which we believe contributes to better visual improvement.The link to the video can be found at: https://youtu.be/RIFi4ecWAhQ.
Antimicrobial Chemotherapy has a Linear Relationship to the Proportion of Gram-Negative Isolates from Pediatric Burn Wounds
Authors: Welk Alexa , Herrnberger Myriam , Engel Veronika , Dennebaum Martin , von Sochaczewski Christina , Gehring Stephan 
Published: January 2018

AbstractWound infection in burns is a relevant cause of morbidity and mortality in children. We aimed to determine the relationship between antibacterial chemotherapy and Gram-negative burn wound colonization and infection. All children admitted to the pediatric intensive care unit for burn trauma from June 1, 2005 to January 31, 2013 were included. We obtained 141 wound samples, of which 88 (65.7%) showed growth of Gram-positive bacteria. Treatment with antimicrobial chemotherapy was necessary in 23 (31.1%) patients. The proportion of Gram-negative isolates seems to increase linear from 12.5% (95% confidence interval (CI): 4.4%–28.7%) without antibacterial chemotherapy to 36.8% (95% CI: 25.5%–49.6%) with one to 48.9% (95% CI: 35.3%–62.8%) with 2 antimicrobial agents. The Odds ratio for a Gram-negative isolate, in comparison to patients without antibacterial chemotherapy, increased from 4.083 (95% CI: 1.140–15.961) for one administered substance to 6.708 (95% CI: 1.832–26.786) if 2 or more were used.
Conclusion We found that antibacterial chemotherapy seems to facilitate burn wound colonization and results in an increased number of gram-negative isolates from children with burn wounds.
Rotational 3D printing of damage-tolerant composites with programmable mechanics
Authors: Raney Jordan R. , Compton Brett G. , Mueller Jochen , Ober Thomas J. , Shea Kristina , Lewis Jennifer A. 
Published: January 2018

Significance
Natural composites exhibit hierarchical and spatially varying structural features that give rise to high stiffness and strength as well as damage tolerance. Here, we report a rotational 3D printing method that enables exquisite control of fiber orientation within engineered composites. Our approach broadens their design, microstructural complexity, and performance space by enabling site-specific optimization of fiber arrangements within short carbon fiber–epoxy composites. Using this approach, we have created composites with programmable strain distribution and failure as well as enhanced damage tolerance.
Infectious virus in exhaled breath of symptomatic seasonal influenza cases from a college community
Authors: Yan Jing , Grantham Michael , Pantelic Jovan , Bueno de Mesquita P. Jacob , Albert Barbara , Liu Fengjie , Ehrman Sheryl , Milton Donald K. ,   EMIT Consortium, Adamson Walt , Beato-Arribas Blanca , Bischoff Werner , Booth William , Cauchemez Simon , Ehrman Sheryl , Enstone Joanne , Ferguson Neil , Forni John , Gilbert Anthony , Grantham Michael , Grohskopf Lisa , Hayward Andrew , Hewitt Michael , Kang Ashley , Killingley Ben , Lambkin-Williams Robert , Mann Alex , Milton Donald , Nguyen-Van-Tam Jonathan , Noakes Catherine , Oxford John , Palmarini Massimo , Pantelic Jovan , Wang Jennifer , Bennett Allan , Cowling Ben , Monto Arnold , Tellier Raymond 
Published: January 2018

Significance
Lack of human data on influenza virus aerosol shedding fuels debate over the importance of airborne transmission. We provide overwhelming evidence that humans generate infectious aerosols and quantitative data to improve mathematical models of transmission and public health interventions. We show that sneezing is rare and not important for—and that coughing is not required for—influenza virus aerosolization. Our findings, that upper and lower airway infection are independent and that fine-particle exhaled aerosols reflect infection in the lung, opened a pathway for a deeper understanding of the human biology of influenza infection and transmission. Our observation of an association between repeated vaccination and increased viral aerosol generation demonstrated the power of our method, but needs confirmation.
Origins of low-symmetry phases in asymmetric diblock copolymer melts
Authors: Kim Kyungtae , Arora Akash , Lewis Ronald M. , Liu Meijiao , Li Weihua , Shi An-Chang , Dorfman Kevin D. , Bates Frank S. 
Published: January 2018

Significance
We demonstrate that low-molecular weight asymmetric diblock copolymer melts can form multiple metastable liquid states at a common temperature, dependent on the processing history. Formation of ordered self-assembled micelles at low temperatures shapes the number density of the mesoscopic particles, which is preserved upon heating above the order–disorder transition temperature. Cooling returns the liquid to the same crystalline state reflecting a memory—a type of hidden symmetry—imprinted in the fluid. These surprising results are explained based on the large energetic penalty associated with fusing or fragmenting micelles in the highly structured liquid state. This work reveals concepts related to spontaneous symmetry breaking in self-assembled soft materials including surfactant-based systems.
Influence of water and enzyme SpnF on the dynamics and energetics of the ambimodal [6+4]/[4+2] cycloaddition
Authors: Yang Zhongyue , Yang Song , Yu Peiyuan , Li Yanwei , Doubleday Charles , Park Jiyong , Patel Ashay , Jeon Byung-sun , Russell William K. , Liu Hung-wen , Russell David H. , Houk Kendall N. 
Published: January 2018

Significance
The investigation of time-resolved mechanisms of enzymatic reaction with accurate quantum-mechanics method is a holy grail of computational chemistry, and we now develop an efficient method, environment-perturbed transition-state sampling, to study single-molecule trajectories in enzymes and calculate activation barriers. In 2011, the Liu group published evidence for the first monofunctional Diels–Alderase, SpnF, in the biosynthetic pathway of Spinosyn A. We discovered later that the reaction bifurcates to the [4+2] and [6+4] adduct through a single ambimodal transition state. We now elucidate in detail the mechanism of the reaction and show how the SpnF enzyme dynamically controls product formation. Our method will find great application in the design of enzymes to control selectivity, particularly for reactions involving ambimodal transition states.