bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimizing Isobutanol Production in Engineered Cyanobacteria Using High Salinity Stress and Establishment of a Resource Recycling Strategy
Authors: Wu Xiao-Xi , Li Jian-Wei , Xing Su-Fang , Chen Hui-Ting , Song Chao , Wang Shu-Guang , Yan Zhen 
Published: January 2021

Abstract
Background: Isobutanol is an attractive biofuel with advantages. Third-generation biorefineries that convert CO2 into bio-based fuels have drawn considerable attention due to their lower feedstock cost and more ecofriendly refining process. Although autotrophic cyanobacteria have been genetically modified for isobutanol biosynthesis, it is still lack of stable and convenient strategies to improve the production.Results: In this study, we first engineered Synechococcus elongatus for isobutanol biosynthesis by introducing five exogenous enzymes, reaching a production titer of 0.126 g/L at day 20. It was then discovered that high salinity stress can significantly enhance isobutanol production five-fold with a maximal in-flask titer of 0.637 g/L at day 20. A comprehensive analysis of the osmotic-induced cells demonstrated that a series of physiological functional self-adjustment in S. elongatus, including altering metabolic profiles to accumulate redox equivalents, strength in antioxidative ability and weaken in membrane integrity, contributed to the isobutanol production titer. A cultivation system was then developed by mixing wastewater with seawater to grow the engineered cyanobacteria, reaching a similar isobutanol production titer as cultivation in the medium. Conclusions: High salinity stress on engineered cyanobacteria is a practical and feasible biotechnology to optimize isobutanol production. This biotechnology provides a prospect for biofuel production cost-effectively, and simultaneously recycles chemical nutrients from wastewater and seawater.
Analysis and Prediction of Epidemic Infectious Diseases Based on SEIDR Model -- A Case Study of COVID-19 in New York
Authors: Xu Zhigang , Xia Huiling 
Published: January 2021

Abstract
In the epidemic prevention and control of infectious diseases, improper prevention and control can easily lead to a large-scale epidemic. However, the epidemic of diseases follows certain rules, so it is very necessary to simulate the spread of infectious diseases, which can provide reference for the formulation of prevention and control measures. This paper proposes a SEIDR model for analyzing and predicting epidemic infectious diseases. Taking the development situation of COVID-19 in New York City as an example, firstly, the SEIDR model proposed in this paper was compared with the traditional SIR model, and it was found that the SEIDR model was better than the SIR model. Then the SEIDR model and the L-BFGS optimization method were used to fit the early transmission data of COVID-19 in New York City, and important parameters such as infection rate, latent morbidity rate, disease-related mortality and recovery rate were obtained. Moreover, the value of basic regeneration number 𝑅0 between 4.0 and 4.6 proved that the situation of COVID-19 in New York City was relatively serious. Finally, these parameters were used to predict the future development of COVID-19 in New York City, and the turning point of COVID-19 in New York City was found. However, even if the turning point be reached, the development trend of COVID-19 will not be controlled in the short term. Data verification shows that the SEIDR model established in this paper can effectively provide a scientific quantitative index for governments in the prevention and control of COVID-19 and other epidemic infectious diseases.
Consolidated bioprocessing of lignocellulose for production of glucaric acid by an artificial microbial consortium
Authors: Li Chaofeng , Lin Xiaofeng , Ling Xing , Li Shuo , Fang Hao 
Published: January 2021

Abstract
Background: The biomanufacturing of D-glucaric acid has been attracted increasing interest because it is one of the top value-added chemicals produced from biomass. Saccharomyces cerevisiae is regarded as an excellent host for D-glucaric acid production. Results: The opi1 gene was knocked out because of its negative regulation on myo-inositol synthesis, which is the limiting step of D-glucaric acid production by S. cerevisiae. Then we constructed the biosynthetic pathway of D-glucaric acid in S. cerevisiae INVSc1 opi1Δ and obtained two engineered strains, LGA-1 and LGA-C, producing record breaking titers of D-glucaric acid, 9.53 ± 0.46 g/L and 11.21 ± 0.63 g/L D-glucaric acid from 30 g/L glucose and 10.8 g/L myo-inositol in the mode of fed-batch fermentation, respectively. However, LGA-1 was more preferable because of the genetic stability and the outperformance in applications. So far, there have been no reports on D-glucaric acid production from lignocellulose. Therefore, the biorefinery processes including separated hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF) and consolidated bioprocessing (CBP) were investigated and compared. CBP by an artificial microbial consortium composed of Trichoderma reesei Rut-C30 and S. cerevisiae LGA-1 was found to have relatively high D-glucaric acid titers and yields after 7 d fermentation, 0.54 ± 0.12 g/L D-glucaric acid from 15 g/L Avicel, and 0.45 ± 0.06 g/L D-glucaric acid from 15 g/L steam exploded corn stover (SECS), respectively. In attempts to design the microbial consortium for more efficient CBP the team consisted of the two members, T. reesei Rut-C30 and S. cerevisiae LGA-1, was found to be the best with excellent work distribution and collaboration.Conclusions: Two engineered S. cerevisiae strains, LGA-1 and LGA-C, with high titers of D-glucaric acid were obtained. This indicates that S. cerevisiae INVSc1 was an excellent host. Lignocellulose is a more preferable substrate than myo-inositol. SHF, SSF and CBP were studied and CBP by an artificial microbial consortium of T. reesei Rut-C30 and S. cerevisiae LGA-1 was found to be promising because of the relatively high titer and yield. T. reesei Rut-C30 and S. cerevisiae LGA-1were proved to be the best teammates for CBP. Further work should be done to improve the efficiency of this microbial consortium for D-glucaric acid production from lignocellulose.
Feasibility study of hospital antimicrobial stewardship analytics using electronic health records
Authors: Dutey-Magni Peter , Gill Martin J , Mcnulty David , Sohal Gurjit , Hayward Andrew , Shallcross Laura 
Published: January 2021

Abstract
Background: Hospital antimicrobial stewardship (AMS) programmes are multidisciplinary initiatives to optimise the use of antimicrobials. Most hospitals depend on time-consuming manual audits to monitor clinicians’ prescribing. But much of the information needed could be sourced from electronic health records (EHRs).Objectives: To develop an informatics methodology to analyse characteristics of hospital AMS practice using routine electronic prescribing and laboratory records.Methods: Feasibility study using electronic prescribing, laboratory and clinical coding records from adult patients admitted to six specialties at Queen Elizabeth Hospital, Birmingham, UK (September 2017–August 2018). The study involved: (1) a review of antimicrobial stewardship standards of care; (2) their translation into concepts measurable from commonly available EHRs; (3) pilot application in an EHR cohort study (n=61,679 admissions).Results: We developed data modelling methods to characterise the use of antimicrobials (antimicrobial therapy episode linkage methods, therapy table, therapy changes). Prescriptions were linked into antimicrobial therapy episodes (mean 2.4 prescriptions/episode; mean length of therapy of 5.8 days) enabling production of several actionable findings. For example, 22% of therapy episodes for low-severity community acquired pneumonia were congruent with prescribing guidelines, with a tendency to use antibiotics with a broader spectrum. Analysis of therapy changes revealed a delay in switching from intravenous to oral therapy by an average 3.6 days [95% CI: 3.4; 3.7]. Performance of microbial cultures prior to treatment initiation occurred in just 22% of antibacterial prescriptions. The proposed methods enabled fine-grained monitoring of AMS practice all the way down to specialties, wards, and individual clinical teams by case mix, enabling more meaningful peer comparison. Conclusions: It is feasible to use hospital EHRs to construct rapid, meaningful measures of prescribing quality with potential to support quality improvement interventions (audit/feedback to prescribers), engagement with front-line clinicians on optimising prescribing, and AMS impact evaluation studies.
Expression of miR-195 and its target gene Bcl-2 in human intervertebral disc degeneration and their effects on nucleus pulposus cell apoptosis
Authors: Lin Xue-Lin , Zheng Zhao-Yun , Zhang Qing-Shan , Zhang Zhen , An You-Zhi 
Published: January 2021

Abstract
Objective: To investigate the expression of miR-195 and its target gene Bcl-2 in intervertebral disc degeneration (IVDD) and its effect on nucleus pulposus (NP) cell apoptosis.Methods: The expressions of miR-195 and Bcl-2 in NP tissues of IVDD patients were quantified by qRT-PCR and Western blotting, respectively. NP cells were divided into Blank group, TNF-α group, TNF-α + miR-NC group, TNF-α + siBcl-2 group, and TNF-α + miR-195 inhibitors + siBcl-2 group. Cell proliferation was detected by MTT assay, cell apoptosis evaluated by flow cytometry, and mitochondrial membrane potential (MMP) tested by JC-1 staining. Moreover, the function of miR-132 on IVDD in vivo was investigated using a puncture-induced IVDD rat model.Results: IVDD patients had significantly increased miR-195 expression and decreased Bcl-2 protein expression in NP tissues. The expression of miR-195 was negatively correlated with the expression of Bcl-2 in IVDD patients. Dual-luciferase reporter gene assay indicated that Bcl-2 was a target gene of miR-195. In comparison with Blank group, TNF-α group showed decreased cell proliferation and MMP, increased cell apoptosis, up-regulated expression of miR-195, Bax and cleaved caspase 3, and down-regulated Bcl-2 protein, while these changes were attenuated by miR-195 inhibitors. Additionally, siBcl-2 can reverse the protective effect of miR-195 inhibitors on TNF-α-induced NP cells. Besides, inhibition of miR-195 alleviated IVDD degeneration and NP cell apoptosis in the rat model.Conclusion: MiR-195 was significantly up-regulated in NP tissues of IVDD patients, and inhibition of miR-195 could protect human NP cells from TNF-α-induced apoptosis via upregulation of Bcl-2.
Associations between antiretroviral therapy–related experiences and mental health status among people living with HIV in China: A prospective observational cohort study
Authors: Xie Jinzhao , Wang Zixin , Li Quanmin , He Qiangsheng , Xu Guohong , Li Yonghong , Zhou Kai , Li Linghua , Gu Jing 
Published: January 2021

Abstract
Background: Mental health problems (e.g., depression and anxiety) are among the most commonly reported comorbidities of HIV. Antiretroviral therapy (ART) coverage has increased sharply. The purposes of this prospective cohort study were to investigate the ART-related experiences and whether they were associated with mental health problems among a sample of people living with HIV undergoing ART in China.Methods: The participants were 400 people living with HIV who had started ART for the first time in Guangzhou city. They were followed-up one-year after ART initiation. Probable depression and moderate/severe anxiety were measured at baseline and Month 12, while experiences related to ART (e.g., side effects and regained self-confidence) were measured at Month 6. Univariate and multivariate logistic regressions were used to explore the associations between baseline characteristics, ART-related experiences and mental health status.Results: Among the 300 participants (75.0%) who completed all three surveys, a significant decline in prevalence of probable depression (23.0% at baseline vs. 14.0% at Month 12, P = 0.002) and moderate/severe anxiety (14.7% at baseline vs. 8.7% at Month 12, P = 0.023) was observed during the follow-up period. After adjustment for mental health status and potential confounders at baseline, a number of ART-related experiences at Month 6 were associated with probable depression and/or moderate/severe anxiety measured at Month 12. Improved physical health, relationships with sexual partners, and self-confidence were associated with decreased mental health issues, while the side effects of ART, AIDS-related symptoms, and inconvenience in daily life due to ART use were associated with increased mental health issues.Conclusions: ART-related experiences were associated with mental health problems, tailored mental health promotion interventions targeting these experiences are needed.
CHALLENGES OF COVID-19 AEROMEDICAL RETRIEVAL: LESSONS LEARNT FROM CONDUCTING AEROMEDICAL TRANSFERS DURING A PANDEMIC
Authors: Ganesh Gihan , Christie Gayle , McIlroy David , Dutton Shelley , Challen Andrew 
Published: January 2021

ABSTRACT
The COVID-19 pandemic has presented a unique and challenging environment for aeromedical organisations. We present lessons learnt during the development and implementation of our operational processes and procedures at The Royal Flying Doctor Service (RFDS) Western Operations for the transfer of suspected COVID-19 patients. To date, we have conducted 105 such fixed-wing transfers. The unique geography and health care system of Western Australia mandates that long-range, fixed-wing transfers are often required to centralised tertiary care. These lessons learnt provide a framework for the essential logistical, equipment and human factor considerations for developing an effective system. The translation of predominantly hospital-centric protocols into the aviation environment requires careful forethought, effective leadership and teamwork. Conducting COVID-19 suspected aeromedical retrievals significantly impacts all aeromedical retrieval operations and aeromedical personnel that should be realised by an aeromedical organisation.
VENOUS THROMBOEMBOLISM
Authors: MacKellar Rachel 
Published: January 2021

ABSTRACT
Venous thromboembolism (VTE) is the condition in which blood clots form within the venous circulatory system, and consist of DVT (deep vein thrombosis) and PEs (Pulmonary emboli).
It is a common condition, with an estimated life-time risk of 8% and an annual incidence of 0.84-1 per 1000 population1, 2 and represents a significant economic burden: within Australia the annual estimated cost in 2018 being $1.72 billion AUD3.
The condition is considered aeromedically significant for both aircrew and passengers; diagnosis and treatment may have implications on an aviators medical certificate and the general public are often concerned about developing “economy class syndrome”.
This paper reviews the pathophysiology of VTE, the relationship between VTE and its treatment in the aviation environment. It also reviews some of the international aeromedical regulatory guidelines and provides a suggested approach to certification in case of VTE.
Pseudomorphic 9-line silician ferrihydrite and Fe-rich serpentine-group minerals in FeTi oxide-rich ferroan peridotite, Laramie anorthosite complex, Wyoming, U.S.A.
Authors: Evans Bernard W. , Kuehner Scott M. , Joswiak David J. 
Published: January 2021

AbstractLow-temperature hydrous alteration of FeTi oxide-rich ferroan peridotite, Laramie anorthosite complex, Wyoming, produced silician ferrihydrite, cronstedtite, greenalite, hisingerite, and talc. Ferrihydrite occurs as nanocrystals in ~50 nm diameter granules that form monomineralic masses up to 300 μm across. It is inferred to have formed by the replacement of an igneous sulfide such as pyrrhotite. Electron diffraction shows the ferrihydrite to be a 9-line variety. Si-rich cronstedtite formed thin rims around the ferrihydrite, and talc grew patchily around the cronstedtite. Greenalite formed in ~10 μm cracks through all the above minerals and olivine, and hisingerite microveinlets partially replaced olivine. Igneous minerals remaining include olivine Fa46, magnetite, ilmenite, hornblende, biotite, and trace clinopyroxene. Correlations among the constituents of ferrihydrite determined by electron microprobe, including anhydrous totals, indicate progress during the growth of two charge-balanced exchanges involving silica enrichment: an inverse cronstedtite substitution (MgFe2+,Si) (Fe3+Mn3+)–2 and an inverse hydrogarnet substitution SiH–4. The cronstedtite exchange requires charge and size balance across nearest-neighbor T and O crystal sites, suggesting crystal-interior rather than crystal-surface control. Ferrihydrite’s composition reflects time- and space-related variations in the chemical potentials of components in the hydrous fluid at the site of alteration. An upper limit for SiO2 of 14–15 wt%, or ≈1.0 Si per 5-cation formula unit, would seem to correspond to the limit of availability in ferrihydrite of tetrahedral sites open to the entry of Si. Our EPMA data, projected to zero SiO2, indicate an anhydrous total of ≈83 wt% for end-member ferrihydrite, a number that matches the formula: Fe10O15·9H2O. The geochemical properties of Laramie ferrihydrite are shared by some samples of altered chondritic and Martian meteorites. Ferrihydrite on Earth commonly occurs as a surface deposit; unlike the Laramie occurrence, these lack the microspatial coherence of replacements/pseudomorphs to show systematic, structure-related element variations. The superior crystal quality of the Laramie ferrihydrite likely contributed to its unique compositional variability.
Re-examination of the heterotype solid solution between calcite and strontianite and Ca-Sr fluid-carbonate distribution: An experimental study of the CaCO3-SrCO3-H2O system at 0.5–5 kbar and 600 °C
Authors: Schiperski Ferry , Liebscher Axel , Gottschalk Matthias , Franz Gerhard 
Published: January 2021

Abstract
Carbonates are excellent carriers for divalent cations such as Ca, Mg, and Sr, and knowledge about their stability and solid solutions is important to understanding the global strontium cycle. To shed light on the topology of the two-phase field between calcite-type and aragonite-type (Ca,Sr)CO3 solid solutions as a function of temperature and pressure, and to learn more about the distribution of Sr and Ca between carbonates and fluid, we studied the system CaCO3-SrCO3-H2O at 600 °C in the pressure range 0.5–5 kbar. Conventional and rapid-quench hydrothermal syntheses were performed using a range of different starting materials. All bulk compositions were within the assumed/postulated two-phase field of calcite-type and aragonite-type (Ca,Sr)CO3 solid solutions. The run products were analyzed by scanning electron microscopy, electron microprobe analysis, and powder X-ray diffraction with Rietveld refinement. The results show that the heterotype solid solution is more extensive than previously assumed, with calcite incorporating up to 20 mol% SrCO3, which is twice as much as previously predicted. The compositional range of the aragonite-type solid solution was identical to that found in the literature. Using the data from this study, an updated version of the phase diagram P-X (Sr) at 600 °C for the CaCO3-SrCO3 system was calculated. The phase diagram does not support a phase transition within the trigonal (Ca,Sr)CO3 solid solution associated with rotational disorder of the CO3-groups. This order-disorder phase transition was previously postulated to explain some observed compositional trends in this system. Our new data are in line with other more recent studies. The distribution of Sr and Ca between the fluid and solid phases D = XSrsolid/XSrfluid is near to 1.0 for calcite-type and on average around 2.0 for aragonite-type solid solutions. This contrasts with silicate-fluid systems in which Sr typically shows a strong preference for the fluid phase compared with Ca.
A Rayleigh model of cesium fractionation in granite-pegmatite systems
Authors: London David 
Published: January 2021

Abstract
The K/Cs ratios of K-feldspars from granitic pegmatites are compared to models derived from the Rayleigh equation. The K/Cs and K/Rb ratios of K-feldspars and micas exhibit decreasing values when plotted against their Cs or Rb contents across cogenetic suites of granites and pegmatites and from margin to core of individual bodies. The trends in elemental ratios conform to Rayleigh fractionation for the crystallization of feldspars and micas from a silicate melt. Within two individual pegmatite bodies, the K/Cs ratio of K-feldspar initially falls more rapidly than the Rayleigh model predicts. That might reflect a local increase in the concentration of Cs relative to K due to the pile-up of incompatible elements in a boundary layer of melt adjacent to the crystal growth front. The addition of an aqueous solution to the Rayleigh model (i.e., the simultaneous crystallization of K-feldspars from melt and from aqueous solution) predicts high and increasing K/Cs ratios of K-feldspars that are not observed in natural rock suites, except when K-feldspars crystallize in miarolitic cavities or when primary K-feldspar recrystallizes to microcline perthite in an open hydrothermal system. In those cases, the Cs content of K-feldspars falls to nil because of the high solubility of Cs in aqueous solution and low compatibility of Cs in K-feldspar. Otherwise, the observed patterns of K/Rb or K/Cs in K-feldspar and micas in pegmatites conform to crystal-melt fractionation in which an aqueous solution plays no part. From the viewpoint of the geochemistry of Cs in pegmatites, these observations give support to the model proposed by Cameron et al. (1949) and endorsed by Jahns (1953a, 1953b).
Copper removal from semiconductor CMP wastewater in the presence of nano-SiO2 through biosorption
Authors: Wang Xiaoyu , Buer Gude , Fan Wei , Gao Lei , Huo Mingxin 
Published: January 2021

Abstract
Copper-bearing wastewater from chemical mechanical planarization (CMP) is a typical semiconductor development byproduct. How to effectively treat Cu2+ in the CMP wastewater is a great concern in the microchip manufacturing industry. In this study, we investigated the potential for the microbial removal of Cu2+ by a multiple heavy metal-resistant bacterium Cupriavidus gilardii CR3. The environmental factors, including pH, nano-SiO2, ionic strengths, and initial concentrations of Cu2+, and adsorption times on the bioremoval of Cu2+ in CMP wastewater were optimized. Under optimal condition, the maximum biosorption capacity for Cu2+ was 18.25 mg g−1 and the bioremoval rate was 95.2%. The Freundlich model is described well for the biosorption of Cu2+ in CMP wastewater in the presence of nano-SiO2 (R2 = 0.99). The biosorption process obeyed the pseudo-second-order kinetic equation (R2 &gt; 0.99). In the column experiment, the advection–dispersion–retention model fitted the breakthrough curve of all experiments well (R2 &gt; 0.95). The attachment coefficient in the sand matrix coated by CR3 biofilm was 2.24–2.80 times as that in clean sand. Overall, C. gilardii CR3 is a promising candidate to remove Cu2+ from CMP wastewater. Nano-SiO2 in CMP wastewater did not inhibit the bioremoval of Cu2+ but showed a slight promotion effect instead.