bluuebunny/crossref_metadata_2025 huggingface dataset:
Low ECD High Performance Invert Emulsion Drilling Fluids: Lab Development and Field Deployment
Authors: Wagle Vikrant , Yami Abdullah , Onoriode Michael , Butcher Jacques , Gupta Nivika
Published: May 2021

The present paper describes the results of the formulation of an acid-soluble low ECD organoclay-free invert emulsion drilling fluid formulated with acid soluble manganese tetroxide and a specially designed bridging package. The paper also presents a short summary of field applications to date.

The novel, non-damaging fluid has superior rheology resulting in lower ECD, excellent suspension properties for effective hole cleaning and barite-sag resistance while also reducing the risk of stuck pipe in high over balance applications.

95pcf high performance invert emulsion fluid (HPIEF) was formulated using an engineered bridging package comprising of acid-soluble bridging agents and an acid-soluble weighting agent viz. manganese tetroxide. The paper describes the filtration and rheological properties of the HPIEF after hot rolling at 300oF. Different tests such as contamination testing, sag-factor analysis, high temperature-high pressure rheology measurements and filter-cake breaking studies at 300oF were performed on the HPIEF. The 95pcf fluid was also subjected to particle plugging experiments to determine the invasion characteristics and the non-damaging nature of the fluids.

The 95pcf HPIEF exhibited optimal filtration properties at high overbalance conditions. The low PV values and rheological profile support low ECDs while drilling. The static aging tests performed on the 95pcf HPIEF resulted in a sag factor of less than 0.53, qualifying the inherent stability for expected downhole conditions.

The HPIEF demonstrated resilience to contamination testing with negligible change in properties.

Filter-cake breaking experiments performed using a specially designed breaker fluid system gave high filter-cake breaking efficiency. Return permeability studies were performed with the HPIEF against synthetic core material, results of which confirmed the non-damaging design of the fluid.

The paper thus demonstrates the superior performance of the HPIEF in achieving the desired lab and field performance.
Development of Drilling Fluid Advisory System Utilizing Bayesian Network
Authors: Al-Yami Abdullah Saleh , Wagle Vikrant B , Al-Rubaii Mohammed Murif , Abubacker Ziaudeen
Published: May 2021

Using the right drilling fluid with optimal rheology and filtration properties is one of the most important factors in successful drilling and completion operations. Designing the right drilling fluid depends on a variety of factors viz. formation lithology, wellbore geometry, temperature, pressure, and drilling objectives. To the best of the author's knowledge there is no standard drilling fluid advisory system to aid drilling engineers and scientists to formulate effective drilling fluids systems for the entire well sections.

The paper describes a drilling fluid advisory system based on Artificial Bayesian Intelligence. The advisory system includes a Bayesian decision network (BDN) model that receives inputs and outputs recommendations based on Bayesian probability determinations. This advisory system has been designed to aid drilling engineers when designing drilling fluids for their operations. This paper describes a module that was created in this advisory system. This module was created based on several inputs viz. well geometry (vertical and horizontal), temperature, pressure, productivity.

To create the drilling fluids module within the advisory system, a number of drilling fluid specialists/experts were interviewed to gather the information required to determine the best practices as a function of the above inputs. These best practices were then used to build decision trees that would allow the user to take an elementary data set and end up with a decision that honors the best practices. The designing process of this advisory system also included a number of standard lab tests that start from quality assurance, initial designing and finally using field samples to confirm the success of the application.

The study also discusses several field cases that validate the drilling fluids advisory system. The novel drilling fluid advisory system based on Artificial Bayesian Intelligence has been designed to aid drilling engineers and scientists to formulate effective drilling fluids systems for the entire well sections.
Is early surgical intervention effective for traumatic severe cervical spinal cord injury?
Authors: Yamamoto Koji , okuda akinori , Maegawa Naoki , Konishi Hironobu , Miyazaki Keita , Tada Yusuke , Kogeichi Yohei , Takano Keisuke , Asai Hideki , Kawai Yasuyuki , Urisono Yasuyuki , Shigematsu Hideki , Kawamura Kenji , Fukushima Hidetada , Tanaka Yasuhito
Published: May 2021

Background

This study aimed to determine whether surgery within 24 h improves the neurological prognosis and reduces the complications associated with surgery for traumatic severe cervical spinal cord injury (CSCI).
Methods

The data of 42 patients with traumatic severe CSCI with American Spinal Injury Association (ASIA) Impairment Scale (AIS) grades of A–B who underwent surgery between December 2007 and May 2018 were retrospectively reviewed. The participants were divided into early surgery (< 24 h) and late surgery (> 24 h) groups. Using inverse probability of treatment weighting (IPTW) with propensity score adjustment for confounding factors, the AIS grade before and 1 month following surgical treatment as the primary outcome were compared. The secondary outcome was the intensive care unit length of stay (ICU-LOS) and occurrence of respiratory complications and cardiac arrest.
Results

In the early surgery group (n = 32, 76%), the average time to surgery was 10.25 h (4–23 h). The IPTW analysis indicated significant differences in neurological improvement according to the AIS grade at 1 month following surgery (odds ratio [OR]: 17.1 95% confidence interval [Cl]: 1.9–156.7, p = 0.012), ICU-LOS > 7 days (OR: 0.14 95% Cl: 0.02–0.90, p = 0.04), respiratory complications (OR: 0.08 95% Cl: 0.01–0.73, p = 0.03), and cardiac arrest (OR: 0.13 95% Cl: 0.02–0.85, p = 0.03).
Conclusions

Early surgery (within 24 h) for traumatic severe CSCI may be effective in improving the neurological prognosis, and preventing a long ICU-LOS and postoperative complications.
TNFɑ-induced LDL cholesterol accumulation involve elevated LDLR cell surface levels and SR-B1 downregulation in human arterial endothelial cells
Authors: Okoro Emmanuel Ugochukwu
Published: May 2021

Excess lipid droplets are frequently observed in arterial endothelial cells at sites of advanced atherosclerotic plaques. Here, the role of tumor necrosis factor alpha (TNFɑ) in modulating low density lipoprotein (LDL) content in confluent primary human aortic endothelial cells (pHAECs) was investigated. TNFɑ promoted up to 2 folds increase in cellular cholesterol, which was resistant to ACAT inhibition. The cholesterol increase was associated with increased 125I-LDL surface binding. Using the non-hydrolysable label, Dil, TNFɑ could induce a massive increase in Dil-LDL by over 200 folds. The elevated intracellular Dil-LDL was blocked with excess unlabeled LDL and PCSK9, but not oxidized LDL (oxLDL), receptor associated protein (RAP), or apolipoprotein (apoE) depletion. Moreover, TNFɑ-induced increase of LDL-derived lipids was elevated through lysosome inhibition. Using specific LDLR antibody, the Dil-LDL accumulation was reduced by over 99%. Effects of TNFɑ included LDLR cell surface increase by 138%, and very large increases in ICAM-1 total and surface proteins, respectively. In contrast, that of scavenger receptor B1 (SR-B1) was reduced. Additionally, LDLR antibody bound rapidly in TNFɑ-treated cells by about 30 folds, inducing a migrating shift in the LDLR protein. The effect of TNFɑ on Dil-LDL accumulation was inhibited by the antioxidant tetramethythiourea (TMTU) dose-dependently, but not by inhibitors against NF-κB, stress kinases, ASK1, JNK, p38, or apoptosis caspases. Grown on transwell inserts, TNFɑ did not enhance apical to basolateral LDL cholesterol or Dil release. It is concluded that TNFɑ promotes LDLR functions through combined increase at the cell surface and SR-B1 downregulation.
Weaning and Extubation Assisted with Conversational Hypnosis: A systematic review
Authors: Wormser Johan , Romanet Christophe , Bellaïche Aurel , Philippart François
Published: May 2021

Background: Patients admitted in intensive care units often receive mechanical ventilation. Prior to extubation, weaning process could be a major cause of dyspnea and anxiety in awake intubated patients. Hypnosis is commonly used to manage anxiety and pain. Our hypothesis is that hypnosis would decrease stress during the weaning and extubation process.Methods: This systematic review follows PRISMA Guidelines and was registered in PROSPERO (CRD42020171445). Web of Science, MEDLINE and Cochrane Central Register of Controlled Trials databases were searched until 11 March 2020. We included all interventional trials assessing hypnotherapy for intubated patients whom were undergoing weaning or extubation. Two of the authors independently screened studies, extracted data and assessed risk of bias from identified trials.Results: One study fulfilled our selection. This case series included 2 patients. Eleven sessions were completed. Dyspnea was not assessed/reported. Hypnotherapy decreased anxiety during the weaning process from a median of 1 point (Interquartile Range: 1.0-2.5). Increase in oxygen saturation is also reported. There was no evidence of neither an anxiety reduction or an oxygen saturation improvement. This is due to the scarcity of publication and the methodological design of the one selected study.Conclusions: We cannot conclude whether or not hypnosis could be recommended in the weaning process of intubated patients. Further studies are needed to assess hypnosis effects.Registration: The present systematic review was registered in the International prospective register of systematic reviews (PROSPERO) under registration number CRD42020171445.
Genomic Signatures of Pre-Resistance in Mycobacterium tuberculosis
Authors: Ortiz Arturo Torres , Coronel Jorge , Vidal Julia Rios , Bonilla Cesar , Moore David , Gilman Robert , Balloux Francois , Kon Onn Min , Didelot Xavier , Grandjean Louis
Published: May 2021

Recent advances in bacterial whole-genome sequencing have resulted in the identification of a comprehensive catalogue of genomic signatures of antibiotic resistance in Mycobacterium tuberculosis. With a view to pre-empting the emergence of drug-resistance, we hypothesized that pre-existing balanced polymorphisms in drug susceptible genotypes (“pre-resistance mutations”) could increase the risk of acquiring antimicrobial resistance in the future.
In order to identify a pathogen genomic signature of future drug resistance we undertook whole-genome sequencing on 3135 culture positive isolates from different patients sampled over a 17-year period in Lima, Peru.
Reconstructing ancestral whole genomes on time-calibrated phylogenetic trees we identified no single drug resistance in Peru predating 1940. Moving forward in evolutionary time through the phylogenetic tree from 1940, we apply a novel genome-wide survival analysis to determine the hazard of drug resistance acquisition at the level of lineage, mono-resistance state, and single-nucleotide polymorphism. We demonstrate that lineage 2 has a significantly higher incidence of drug resistance acquisition than lineage 4 (HR 3.36, 95% CI 2.10 - 5.38,p-value =4.25×10-7) and estimate that the hazard of evolving rifampicin following isoniazid resistance acquisition is 14 times that of genomes with a susceptible background (HR 14.45,95% CI 8.46 - 15.50, p-value<10−15). Our findings are validated in a separate publicly available dataset from Samara, Russia. After controlling for population structure, we also show that a deletion in a gene coding for the cell surface protein lppP predisposes to the acquisition of drug resistance in susceptible genotypes (HR 6.71, 95% CI4.82-11.22, p-value =1.17×10−9).
Prediction of future drug resistance in susceptible pathogens together with targeted expanded therapy has the potential to prevent drug resistance emergence in Mycobacterium tuberculosis and other pathogens. Prospective cohort studies of participants with and with-out these polymorphisms should be undertaken with a view to implementing personalized pathogen genomic therapy. This approach could be employed to preempt and prevent the emergence of drug resistance and other important traits in other organisms.
Biotic Resistance of Native Communities and Alien Propagule Pressure are Consistent Predictors of Invasion Success During Grassland Establishment
Authors: Rojas-Botero Sandra Liliana , Kollmann Johannes , Teixeira Leonardo H.
Published: May 2021

Invasive alien plants challenge ecosystems restoration. Thus, understanding factors determining the establishment of invasive plants is crucial to improve restoration outcomes. Some key drivers of invasibility of plant communities have been studied, but results are inconsistent, and combined effects have not been addressed. We investigated the contribution of three drivers of invasion success during early phases of restoration, i.e., biotic resistance, invasive propagule pressure, and environmental fluctuations.We compared the contribution of these drivers in a series of mesocosms experiments using designed grasslands as a model system, and Solidago gigantea as invasive model species. Two grassland communities were designed according to competitive trait hierarchies with different sowing patterns, reflecting variation in biotic resistance. We then manipulated invader propagule pressure and applied different scenarios of environmental fluctuation, i.e., flood, heat, and N fertilization. Alien biomass was considered as proxy for invasion success, while native biomass represented restoration success.There were consistent effects of biotic resistance to S. gigantea invasion via competitive trait hierarchies in the three experiments. Communities dominated by species with high-competition traits were more resistant regardless of environmental fluctuation. Clumped seeding of the native community reduced invasibility, whereas larger invasive propagule size increased invasion. The effects of environmental fluctuation were less consistent and context-dependent, thus playing a secondary role when compared to biological drivers of invasion. Restoration initiatives on grasslands impacted by invasive plants should consider biotic resistance of the restored community as a key driver and the importance of controlling further arrivals of invasive species during community assembly.
Sequencing of Methylase-Accessible Regions In Integral Circular Extrachromosomal DNA Reveals Differences In Chromatin Structure
Authors: Chen Weitian , Weng Zhe , Xie Zhe , Xie Yeming , Zhang Chen , Chen Zhichao , Ruan Fengying , Wang Juan , Sun Yuxin , Fang Yitong , Guo Mei , Tong Yiqin , Li Yaning , Tang Chong
Published: May 2021

Background Although extrachromosomal DNA (ecDNA) has been intensively studied for several decades, the mechanisms underlying its tumorigenic effects have been revealed only recently. In the majority of conventional sequencing studies, the high-throughput short-read sequencing largely ignores the epigenetic status of most ecDNA regions except for the junctional areas. MethodsHere, we developed the sequencing of enzyme-accessible chromatin in circular DNA (CCDA-seq) method, which uses methylase to label open chromatin without fragmentation and exonuclease to enrich the ecDNA sequencing depth, followed by long-read nanopore sequencing. ResultsUsing CCDA-seq, we observed significantly different patterns in nucleosome/regulator binding in ecDNA at a single-molecule resolution. ConclusionsThese results deepen the understanding of ecDNA regulatory mechanisms.
Mercury Distribution in an Upper St. Lawrence River Wetland Dominated by Cattail (Typha Angustifolia)
Authors: Brahmstedt Evie S , Crespo Carla N Ayala , Holsen Thomas M , Twiss Michael
Published: May 2021

Legacy mercury (Hg) exists in Upper St. Lawrence River wetland hydric soils and is impacted by a new water level management plan (established in 2017) implemented to restore biodiversity and reduce the monotypic nature of riparian wetlands, currently dominated by Typha spp.. The distribution of Hg within the various components of a riparian wetland provides insight into potential impacts of water level fluctuations. Hydric soil represents 83% of the wetland Hg burden while wetland plant biomass contributed 17%, mostly due to organic detritus (13%). Although Typha roots had a bioconcentration factor of 1.2 (relative to hydric soils) and had the highest total Hg among living tissues (25 ± 9.3 ng/g dry wt.), detritus had the highest overall Hg content (110 ± 53 ng/g dry wt.). While root tissue Hg correlated significantly with soil Hg (p = 0.045), it was determined here that Typha spp. has limited use as a biomonitor in wetlands with low levels of Hg contamination, as in this ecosystem. Hg contained within the organic detritus contributed more to the overall Hg burden in these monotypic Typha wetlands than any other tissue or biomass component analyzed. Consequently, shifts in the plant community that are expected to result from a new water level management plan may alter Hg storage within these wetlands and affect its mobility in this ecosystem.
Seasonal Variation in Acute Dacriocystitis
Authors: Ertan Elif , İnan Sibel , Doğan İsmet , İnan Ümit Übeyt
Published: May 2021

Objectives: Seasonal variation is possible in some medical conditions.Acute dacryocystitis is very disturbing clinical picture and can develop in any time of the year in patients with lacrimal duct obstruction. We aimed to investigate whether there is a seasonal relationship with the emergence of acute dacryocystitis.Material and Methods:The files of the patients who applied to the ophthalmology outpatient clinic with the complaints of tearing and discharge for five years and diagnosed with acute dacryocystitis were analyzed retrospectively. Age, gender, date of occurrence of the complaints and the date of diagnosis of acute dacryocystitis were recorded. In order to determine the seasonal relationship, the data regarding the number of cases who applied every month of the year were analyzed statistically by Rayleigh test.Results: The mean age of 60 patients (45 females, 15 males) included in the study was 54.70 ± 16.80 years. It was found that all patients were not equally likely to arrive at the hospital and the onset of their complaints throughout the months of the year (p <0.05). The frequency of applications was higher between May and August.Conclusion: There seems to be a seasonal relationship with the timing of the acute dacryocystitis. In our series, more acute dacryocystitis cases were encountered in the first spring-summer months. The reason for the increase of acute dacryocystitis cases in hot seasons of the year may be due to the increase in infectious agents in these seasons.
An Empirical Study of Supply Chain Frangibility and Risk Management in Indian Automobile Industry
Authors: Ankit Arora , Rajesh Rajagopal
Published: May 2021

The automobile sector in India is one the key segment of Indian economy as it contributes to 4% of India’s GDP and 5% of India’s Industrial production. The supply chain of any firm is generally dependent on six driving factors out of which three are functional (information, inventory, and facilities) and 3 are logistic (sourcing, pricing, and transportation). The risk causing factors in supply chains consists of various levels of sub-factors under them. Say for instance, under supply risk, the sub-factors can be poor logistics at supplier end, poor material quality etc., under demand risk, the sub-factors can be inaccurate demand forecasting, fluctuating demand, bullwhip effect, and under logistics risk, the sub-factors can be poor transportation network, shorter lead time, stock outs. Through this study, we observe to find the effect of these factors in the supply chain. We use Failure Mode and Effect Analysis (FMEA) technique to prioritize the various types of risk into zones namely high, medium and low risk factors. Also, we use the Best Worst Method (BWM), a multi-criteria decision-making technique to find out the overall weightings of different risk factors. The combination of these methods can help an organization to prioritize various risk factors and proposing a proper risk mitigation strategy leading to increase in overall supply chain efficiency and responsiveness.
Promotive Effects of Cellulolytic Enzymes Produced by Biomass-Degrading Bacteria on Saccharification of Different Pretreated Corn Stovers
Authors: Wu Yanwen , Shrestha Sarita , Guo Haipeng , Zhang Jinchi , Wang Haisong , Qin Wensheng
Published: May 2021

Enzymatic saccharification of corn stover can be enhanced by partially replacing commercial enzymes with bacterial crude enzyme extracts. Three bacteria, Bacillus sp. A0, Bacillus sp. CH20S1, and Exiguobacterium sp. AS2B, were cultured in a media with corn stover as the substrate. The cultural conditions were monitored and optimized to maximize CMCase and xylanase activity in the crude enzyme extracts. After 72 h of hydrolysis of corn stover with diluted crude enzymes (DCE) from the three strains, reducing sugars were released from non-pretreated and pretreated corn stovers. Values of the released sugars ranged from 48.23–71.69 mg g− 1, which were lower than those released by commercial cellulase (100–400 mg g− 1). The synergistic effects were observed when 12 FPU g− 1 and 4 FPU g− 1 of commercial cellulase were added to the DCE of the CH20S1 strain producing 315.90 mg g− 1 and 320.65 mg g− 1 reducing sugars, respectively. It was shown that an effective combination of bacterial DCE with commercial enzymes could achieve more cost-efficient saccharification of lignocellulosic biomass compared to either of the two enzymes used alone.
Dissipation Pattern of Five Pesticides in Vegetable Samples
Authors: Shoeb Mohammad , Munia Zerin Sultana , Nahar Nilufar
Published: May 2021

Pesticides are frequently used in agricultural fields in Bangladesh. Residual pesticides in vegetable samples above maximum residue limits (MRL) are illegal use of pesticides and absence of Good Agricultural Practice (GAP). The Government made Safe Food Law to ensure safe food for all citizens of the country. To assess the dissipation of pesticides in vegetable samples for consumer safety, five locally banded pesticides i.e., Vitaban (chlorpyrifos), Double (mixture of imidacloprid and cypermethrin), Nitro (mixture of chlorpyrifos and cypermethrin), Acephate and Reeva (lambda cyhalothrin) were applied to eight different vegetables at the dose which farmers apply in their field in a large vegetable cultivation area. Samples were harvested from the farmer’s fields at 2h (0 day) after application of pesticides and analyzed at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 days keeping them at ambient temperature. Samples were extracted following Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method and cleaned up using primary secondary amine (PSA), and finally analysed by Gas Chromatograph Electron Captured Detector (GC-ECD. Limit of detection (LOD) and limit of quantification (LOQ) of chlorpyrifos, cypermethrin, imidacloprid, acephate and lambda cyhalothrin were 0.019 and 0.057, 0.019 and 0.057, 0.009 and 0.027, 0.019 and 0.057, and 0.009 and 0.057 µg/mL, respectively. Recoveries of these pesticides in these vegetables samples were within acceptable range of 74–110%. Level below MRL value of cypermethrin was found to be 2–5 days while chlorpyrifos, imidacloprid, acephate and lambda cyhalothrin treated vegetables were varied 3–8 days and considered to consume after these days, respectively.
Effect of Long-term Low Concentrations of TiO2 Nanoparticles on Dewaterability of Activated Sludge and the Relevant Mechanism: The Role of Nanoparticle Aging
Authors: Jiang Chengyu , Chen Qingjin
Published: May 2021

Nanoparticles can undergo aging phenomena that change their physical and chemical properties in sewage treatment systems. However, the effect of aged nanoparticles under long-term low concentrations on the dewatering performance of activated sludge in sewage treatment systems has not been reported yet. Here, we compared the chronic effects of pristine and aged TiO2 nanoparticles on sludge dewatering index including specific resistance to filtration (SRF) and bound water (BW) in the sequencing batch reactor (SBR) with the µg/L concentration levels and the relevant mechanisms were analyzed. The results show that the aging experiment in sludge supernatant could change the photosensitivity and water stability of nanoparticles, which was mainly due to the changes in the zeta potential and energy band of the particle, and ultimately attributed to the combined effect of particle surface inclusions such as organic matter and inorganic salt. At 10µg/L, nanoparticles could reduce the dewaterability of sludge, but at 100µg/L, nanoparticles could improve the dewaterability of sludge, because 10µg/L promoted the secretion of extracellular polymeric substance (EPS), regulated the structure of sludge flora and increased the abundance of secreting quorum sensing-acyl-homoserine lactones (QS-AHL) and EPS genera, while the corresponding exposure results of 100µg/L were the opposite, due to the damage and necrosis exposure effects of 100µg/L under long-term light, which reduced EPS production and increased sludge density. Interestingly, aging could alleviate the effects of two exposure concentrations on sludge dewatering, mainly being attributed to the decrease of the photoactivity of nanoparticles. The results of this study show that environmental aging could slow down, but cannot reverse the results of exposure to specific concentrations of nanoparticles. However, the ecological effects of photosensitive nanoparticles with two environmentally-relevant concentration levels of ug/L were significantly different, which should be refined and confirmed again in freshwater environment to provide a basis for subsequent scientific management and control of photosensitive nanoparticles.
Direct visualization of orbital electron occupancy
Authors: Shang Tongtong , Xiao Dongdong , Meng Fanqi , Rong Xiaohui , Liu Xiaozhi , Li Xinyan , Zhang Qinghua , Wen Yuren , Wang Xuefeng , Su Dong , Hu Yong-Sheng , Li Hong , Yu Qian , Zhang Ze , Petricek Vaclav , Wu Lijun , Gu Lin , Zuo Jian-Min , Zhu Yimei , Nan Ce Wen , Zhu Jing
Published: May 2021

Orbital is one of the primary physical parameters that determine materials’ properties. Currently, experimentally revealing the electron occupancies of orbitals under the control of external field remains a big challenge due to the stringent requirements for samples such as the atomically sharp surface or defect-free large-size single crystals. Here, we developed a method with the combination of quantitative convergent-beam electron diffraction and synchrotron powder X-ray diffraction, and demonstrated the visualization of the real-space orbital occupancy by choosing LiCoO2 as a prototype. Through multipole modelling of the accurately measured structure factors, we found the opposite changes of Co t2g and eg orbital occupancies under different electrochemical states which can be well-correlated with the CoO6 octahedra distortion. This robust method provides a feasible route to quantify the real-space orbital occupancy on small-sized particles, and opens up a new avenue for exploring the orbital origin of physical properties for functional materials.
Genetic determinants of ammonia excretion in nifL mutants of Azotobacter vinelandii
Authors: Mus Florence , Khokhani Devanshi , Rugoli Esther , Dixon Ray , Ané Jean-Michel , Peters John
Published: May 2021

The ubiquitous diazotrophic soil bacterium Azotobacter vinelandii has been extensively studied as a model organism for biological nitrogen fixation (BNF). In A. vinelandii, BNF is regulated by the NifL-NifA two-component system, where NifL acts as an anti-activator that tightly controls that activity of the nitrogen fixation specific transcriptional activator, NifA, in response to redox, nitrogen, and carbon status. While several studies reported mutations in A. vinelandii nifL resulted in the deregulation of nitrogenase expression and the release of large quantities of ammonia, knowledge about the specific determinants for this ammonia-excreting phenotype is lacking. In this work, we report that only specific disruptions of nifL lead to large quantities of ammonia accumulated in liquid culture (~ 12 mM). The ammonia excretion phenotype is solely associated with deletions of NifL domains combined with the insertion of a promoter sequence in the opposite orientation to nifLA transcription. We further demonstrated that the strength of the inserted promoter could influence the amounts of ammonia excreted by affecting rnf1 gene expression as an additional requirement for ammonia excretion. These ammonia-excreting nifL mutants significantly stimulate the transfer of fixed nitrogen to rice. This work defines the discreet determinants that bring about A. vinelandii ammonia excretion and demonstrates that strains can be generated through simple gene editing to provide promising biofertilizers capable of transferring nitrogen to crops.
Combining Banker Plants To Achieve High Pest Control Efficiency In Multi-Pest, Multi-Natural Enemy Cropping Systems
Authors: Chen Xu , Jaworski Coline C. , Dai Huijie , Liang Yuyong , Guo Xiaojun , Wang Su , Zang Lian-Sheng , Desneux Nicolas
Published: May 2021

Banker plants increase biological pest control by supporting populations of non-pest arthropod species used as alternative hosts or prey by natural enemies. Due to the specificity of trophic interactions, banker plants may not efficiently promote natural enemies with different ecologies. Yet in most cropping systems different pest species are present together and require different biocontrol agents to efficiently control them. In the present study, we tested the combined use of two banker plants and their associated prey / host to enhance populations of the specialist parasitoid Encarsia formosa targeting the main tomato pest Bemisia tabaci, and a polyphagous ladybird Propylea japonica targeting the secondary pest Myzus persicae in tomato crops. In a laboratory and a greenhouse experiment, we measured the abundances of these four species using the Ricinus communis – Trialeurodes ricini banker plant system alone, in combination with the Glycines max – Megoura japonica system, or in absence of banker plants. We found that the first banker plant system enhanced populations of E. formosa, resulting in higher control of B. tabaci populations and the suppression of their outbreak in both our laboratory and greenhouse experiment. Conversely, abundances of P. japonica were not affected by this first system, but were significantly increased when the second was present. This resulted in high control of M. persicae populations and the suppression of their early and late outbreaks. Our study demonstrates the potential for combined banker plants to provide long-term, sustainable control of multiple pests by their target natural enemies in complex agroecosystems.
Estimation of The Fractal Dimension of Thyroid Nodules As A Complementary Diagnostic Tool For Predicting Malignancy
Authors: Lothaire Philippe , Uzureau Pierrick , Boudjelta Karim Zouaoui , Nagy Nathalie , Michiels Carine , Carletti Timoteo
Published: May 2021

PurposeUltrasound-guided fine-needle aspiration is the most sensitive investigation procedure in the evaluation of patients with thyroid nodules; however, despite the level of achieved precision, it is still impossible to preoperatively discriminate between follicular adenomas and carcinomas. Thus, no current detection tool of thyroid nodule has both high sensitivity and high positive predictive value for the diagnosis of thyroid cancer. Ultrasound images provide information that are currently missed due to visual interpretation, including the roughness of the echotexture. However, such information can be retrieved using the measurement of the fractal dimension (FD).Material and methodsAccording to the box-counting method, we measured the FD of the echotexture of ultrasound images of 13 benign thyroid nodules and 14 malignant thyroid nodules compared to normal thyroid tissue from 10 men and 16 women (mean age 40).ResultsThe difference of the FD value between malignant nodules (median FD 2.31) and corresponding normal tissues (median FD 2.184) was significant (p<0.001) while the FD values for the benign nodules (median FD 2.21) and for corresponding normal tissues (median FD 2.231) could not be distinguished (p=0.78).ConclusionsThis preliminary work revealed that FD would be an additional feature to discriminate benign from malignant nodules. A larger sampling is now required to confirm the possible utilization of FD in the thyroid cancer diagnosis in clinical practice.
Nitrogen Transport in a Tundra Landscape: The Effects of Early and Late Growing Season Lateral N Inputs on Arctic Soil and Plant N Pools and N2O Fluxes
Authors: Rasmussen Laura Helene , Zhang Wenxin , Ambus Per , Jansson Per-Erik , Kitzler Barbara , Elberling Bo
Published: May 2021

Understanding N budgets of tundra ecosystems is crucial for projecting future changes in plant community composition, greenhouse gas balances and soil N stocks. Winter warming can lead to higher tundra winter nitrogen (N) mineralization rates, while summer warming may increase both growing season N mineralization and plant N demand. The undulating tundra landscape is inter-connected through water and solute movement on top of and within near-surface soil, but the importance of lateral N fluxes for tundra N budgets is not well known. We studied the quantity and fate of lateral N fluxes in the snowmelt period with a shallow thaw layer, and the late growing season with a deeper thaw layer. We used 15N to trace inorganic lateral N movement in a Low-arctic mesic tundra heath slope in West Greenland and to quantify the fate of N in the receiving area. We found that half of the early-season lateral N input was retained by the receiving ecosystem, whereas half was transported downslope. Plants appear as poor utilizers of early-season N, indicating that higher winter N mineralization may influence plant growth and carbon (C) sequestration less than expected. Still, evergreen plants were better at utilizing early-season N, highlighting how changes in N availability may impact plant community composition. In contrast, later growing season lateral N input was deeper and offered an advantage to deeper-rooted deciduous plants. The measurements suggest that N input driven by future warming at the study site will have no significant impact on the overall N2O emissions. Our work underlines how tundra ecosystem N allocation, C budgets and plant community composition vary in their response to lateral N inputs, which may help us understand future responses in a warmer Arctic.
Preparation of Cotton Fibers Modified With Aromatic Heterocyclic Compounds and Study of Cr(VI) Adsorption Performance
Authors: Huang Zhiyu , Wu Peng , Yin Yankun , Zhou Xiang , Fu Lu , Wang Luoxin , chen shaohua , Tang Xu
Published: May 2021

In order to prepare low-cost and environmentally friendly adsorbent materials for adsorption of heavy metal ion, two kinds of novel modified cottons (C-4-APD and C-2-APZ) were obtained by introducing 4-aminopyridin and 2-aminopyrazine into the surface of degreasing cotton, respectively, and used for the removal of Cr(VI) ions from aqueous solution. The two modified cottons were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), which confirmed the amino groups, pyridine groups and pyrazine groups grafted onto the surface of modified cottons. The maximum adsorption capacities of C-4-APD and C-2-APZ were 73.78 mg/g and 61.34 mg/g, respectively, at the optimum pH of 6 and an initial concentration of 200 mg/g. Kinetic and isotherm studies were carried out to investigate the adsorption behavior of the modified cottons on Cr(VI) ions. The results showed that the adsorption of Cr(VI) ions by modified cottons followed a pseudo-second-order kinetic model, the equilibrium data were in good agreement with the Langmuir isotherm model, and electrostatic and chemisorption may be the main adsorption mechanisms. The recovery and reuse of modified cotton were achieved by washing with 2 wt% thiourea-hydrochloric acid solution (0.5 mol/L concentration of HCl), and the adsorption capacities of C-4-APD and C-2-APZ were maintained above 90% and 80%, respectively, after six cycles.
Lipocalin 2 as Putative Modulator of Local Inflammatory Processes in the Spinal Cord and Component of Organ Cross-talk After Spinal Cord Injury
Authors: Behrens Victoria , Voelz Clara , Müller Nina , Zhao Weiyi , Clarner Tim , Beyer Cordian , Zendedel Adib
Published: May 2021

Lipocalin 2 (Lcn2), an immunomodulator, regulates various cellular processes such as iron transport and defense against bacterial infection. Under pathological conditions, Lcn2 promotes neuroinflammation via the recruitment and activation of immune cells and glia, particularly microglia and astrocytes. Although it seems to have a negative influence on the functional outcome in spinal cord injury (SCI), the extent of its involvement in SCI and the underlying mechanisms are not yet fully known. In this study, using a SCI contusion mouse model, we first investigated the expression pattern of Lcn2 in different parts of the CNS (spinal cord and brain), blood serum and in the liver. Interestingly, we could note a significant increase in Lcn2 throughout the whole spinal cord, in the brain, liver and in blood serum. This demonstrates the diversity of its possible sites of action in SCI. Further, genetic deficiency of Lcn2 (Lcn2-/-) significantly reduced certain aspects of gliosis in the SCI-mice. Taken together, our studies provide first valuable hints, suggesting that Lcn2 is involved in the local and systemic effects post SCI, and might modulate the impairment of different peripheral organs after injury.
A Gain-series Method for Accurate EMCCD Calibration
Authors: Ryan Duncan P. , Dunlap Megan K. , Gelfand Martin P. , Werner James H. , Orden Alan , Goodwin Peter M.
Published: May 2021

Calibration of the gain and digital conversion factor of an EMCCD is necessary for accurate photon counting. We present a new method to quickly calibrate multiple gain settings of an EMCCD camera. Acquiring gain-series calibration data and analyzing the resulting images with the EMCCD noise model more accurately estimates the gain response of the camera. Furthermore, we develop a method to compare the results from different calibration approaches. Gain-series calibration outperforms all other methods in this self-consistency test.
Aberrantly ASF1B Promotes Proliferation and Metastasis of Lung Adenocarcinoma in Vitro Study
Authors: wu liyang
Published: May 2021

ASF1A and ASF1B are two isoforms of the histone H3–H4 chaperone anti-silencing feature 1 (ASF1) found in mammalian cells. To date, however, it remains elusive if they have different physiological functions in lung adenocarcinoma. Here, we identified both ASF1A and ASF1B are elevated in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). ASF1B, but not ASF1A is associated with poor clinical outcomes and act as an independent prognostic factor in LUAD. In vitro studies, knockdown of ASF1B inhibits the proliferation of lung adenocarcinoma through modulating the expression of cyclins and CDK inhibitor (CKI). Moreover, by restraining epithelial-mesenchymal transition (EMT), abnormal of ASF1B could limit metastasis of lung adenocarcinoma. In summary, ASF1B is important in the development of NSCLC and can provide a novel target for lung cancer therapy.
The Relationship Between Additional Heads of the Quadriceps Femoris, the Vasti Muscles and the Patellar Ligament
Authors: Olewnik Łukasz , Ruzik Kacper , Szewczyk Bartłomiej , Podgórski Michał , Aragonés Paloma , Karauda Piotr , Tubbs R. Shane , Sanudo Jose Ramon , Pires Maria Bettencourt , Polguj Michał
Published: May 2021

Introduction: The quadriceps femoris consists of four muscles: the rectus femoris, vastus medialis, vastus intermedius and vastus lateralis. However, the effect of additional quadriceps femoris heads on the vasti muscles and patellar ligaments is unknown.Materials and Methods: One hundred and six lower limbs (34 male and 19 female cadavers) fixed in 10% formalin were examined.Results: On all lower extremities, the vastus lateralis consisted of superficial, intermediate and deep layers. The vastus medialis, on the other hand, consisted of only the longus and obliquus layers. Additional quadriceps femoris heads affected both the vasti muscles and the patellar ligaments.Conclusion: There is a strong correlation between the presence of accessory quadriceps femoris heads and effects on vasti muscles and patellar ligament.
Crystallite fusion in nanocellulose aggregates
Authors: Daicho Kazuho , Kobayashi Kayoko , Fujisawa Shuji , Saito Tsuguyuki
Published: May 2021

Crystallite refers to a single crystalline grain in crystal aggregates, and multiple crystallites form a grain boundary or the inter-crystallite interface1. A grain boundary is a structural defect that hinders the efficient directional transfer of mechanical stress or thermal phonons in crystal aggregates. We observed that grain boundaries within anaggregate of a-few-nanometers-wide fibrillar crystallites of cellulose were crystallized by enhancing their inter-crystallite interactions; multiple crystallites were coupled into single fusion crystals without passing through a melting or dissolving state. Accordingly, the crystallinity of naturally occurring cellulose, which has previously been considered irreversible once decreased2, was recovered, and the thermal energy transfer in the aggregate was significantly improved. Other fibrillar crystallites of chitin also showed a similar fusion phenomenon by enhancing the inter-crystallite interactions. Crystallite fusion in aggregates may occur for other biopolymers.
Histopathological Classification of Canine Endometritis
Authors: Wang Jing-Xuan , Xu Yao , Wang Hao-Ran , Liu Zhi-Yuan , Zhao Qi-Da , Liu Rui-Fang , Wang Xin-Yu , Song Xu-Dong , Xiao Jian-Hua
Published: May 2021

Background: Endometritis is a common disease of the reproductive system in canine dams. The purpose of this study was to develop a standardized histopathological diagnostic classification criteria for canine endometritis. Forty bitches were ovariectomized, and their endometrial tissues were pathologically classified by imaging, anatomical and hematological diagnostic evaluation. Expression of IL-1β, IL-6, and IL-8 mRNAs in uterine tissues were also detected by RT-PCR.Results: Endometritis was grouped into one of four classifications: Cystic endometrial hyperplasia (CEH) (no inflammation), mild inflammatory infiltrate, severe inflammatory infiltrate (hyperplastic) and severe inflammatory infiltrate (atrophic). Direct comparison of the experimental results was complicated by the varying degree of disease severity in individual animals and the diagnostic criteria currently in use by researchers.Conclusions: It is concluded from this study that most of the dogs with clinical manifestations were characterized by endometrial hyperplasia with severe inflammatory infiltration, while the endometrial hyperplasia with mild inflammatory infiltration was not significant. In addition, endometrial cystic hyperplasia-like lesions were also found in asymptomatic bitches who underwent physiological sterilization.
Forest Fragmentation Slows the Decomposition of Coarse Woody Debris in a Subtropical Forest
Authors: Wu Chunsheng , Prescott Cindy E. , Shu Chunjie , Li Baoyong , Zhang Zhijian , Wang Hankun , Zhang Yi , Liu Yuanqiu , Wang G. Geoff
Published: May 2021

Forest fragmentation is increasing rapidly around the world, and edge effects caused by fragmented forests can influence ecosystem functions and ecological processes, including coarse woody debris (CWD) decomposition. Understanding the influencing mechanisms of edge effect on CWD decomposition is needed to assess the effects of forest fragmentation on C cycling and storage. We measured rates of mass loss of CWD of Cinnamomum camphora and Pinus taiwanensis over two years at two distances (0-5m vs. 60m) from a forest edge at two altitudes (215 and 1400 m a.s.l.), in a subtropical forest. In addition, we determined the microbial community of each CWD and the soil beneath via phospholipid fatty acids (PLFAs). Mass loss of CWD 60 m from the forest edge was > 15 % greater than that at the edge (0-5m). Mass loss was positively correlated with the abundance of microbial community and moisture content of the decaying CWD. Distance from edge explained 17.4% of the total variation of the microbial abundance in CWD. The results indicated that the reduced abundance of microbial communities and moisture content at forest edges reduced rates of decomposition of CWD. Long-term experiments with more tree species and more forest types are needed to assess the edge effect's generality.
Comparative Study of the Efficacy and Safety of Plasmakinetic Enucleation of the Prostate in Different Stages Versus Plasmakinetic Resection of the Prostate for Benign Prostate Hyperplasia
Authors: Gu Peng , He Xiaoliang , Zhang Minhao
Published: May 2021

Purpose: To evaluate the clinical curative effect and safety of plasmakinetic enucleation of the prostate (PKEP) in different stages versus plasmakinetic resection of the prostate (PKRP) in the treatment for benign prostate hyperplasia (BPH). Methods: Clinical data of 171 hospitalized patients who suffered from BPH undergoing PKEP or PKRP were collected. All patients were separated into PKEP1 group (n = 44, between July 2018 to June 2019), PKRP group (n = 72, between July 2018 to June 2020), and PKEP2 group (n = 55, between July 2019 to June 2020). General preoperative clinical data, perioperative and postoperative results, and complications were recorded and analyzed among the 3 groups. Results: The hemoglobin change in the PKEP1 and PKEP2 were more slightly than that in the PKRP (P > 0.05). Compared with PKRP, more prostate weight was removed in PKEP1 and PKEP2 (P < 0.05). The operation time of PKEP2 was reduced significantly (P < 0.05), compared with PKEP1 and PKRP. We further found the ratio of operation time to prostate volume(çrsç = 0.630, P < 0.001), and the ratio of operation time to enucleation weight(çrsç = 0.540, P < 0.001) were both decreased with the increase of the number of surgical cases. Compared with preoperative results, postoperative 3-month IPSS, QOL and RUV decreased, while Qmax increased in the 3 groups (P < 0.05). Conclusion: In terms of surgical safety and efficacy, skilled PKEP was comparable with PKRP, in addition it is superior to PKRP in operation time and enucleation weight.