Recent developments in the instrumentation and data analysis of synchrotron small‐angle X‐ray scattering (SAXS) on biomolecules in solution have made biological SAXS (BioSAXS) a mature and popular ...tool in structural biology. This article reports on an advanced endstation developed at beamline 13A of the 3.0 GeV Taiwan Photon Source for biological small‐ and wide‐angle X‐ray scattering (SAXS–WAXS or SWAXS). The endstation features an in‐vacuum SWAXS detection system comprising two mobile area detectors (Eiger X 9M/1M) and an online size‐exclusion chromatography system incorporating several optical probes including a UV–Vis absorption spectrometer and refractometer. The instrumentation and automation allow simultaneous SAXS–WAXS data collection and data reduction for high‐throughput biomolecular conformation and composition determinations. The performance of the endstation is illustrated with the SWAXS data collected for several model proteins in solution, covering a scattering vector magnitude q across three orders of magnitude. The crystal‐model fittings to the data in the q range ∼0.005–2.0 Å−1 indicate high similarity of the solution structures of the proteins to their crystalline forms, except for some subtle hydration‐dependent local details. These results open up new horizons of SWAXS in studying correlated local and global structures of biomolecules in solution.
A new endstation for biological small‐ and wide‐angle X‐ray scattering is detailed, which provides development opportunities for studying correlated local and global structures of biomolecules in solution.
To establish an ideal microenvironment for regenerating maxillofacial defects, recent research interests have concentrated on developing scaffolds with intricate configurations and manipulating the ...stiffness of extracellular matrix toward osteogenesis. Herein, we propose to infuse a degradable RGD-functionalized alginate matrix (RAM) with osteoid-like stiffness, as an artificial extracellular matrix, to a rigid 3D-printed hydroxyapatite scaffold for maxillofacial regeneration. The 3D-printed hydroxyapatite scaffold was produced by microextrusion technology and showed good dimensional stability with consistent microporous detail. RAM was crosslinked by calcium sulfate to manipulate the stiffness, and its degradation was accelerated by partial oxidation using sodium periodate. The results revealed that viability of bone marrow stem cells was significantly improved on the RAM and was promoted on the oxidized RAM. In addition, the migration and osteogenic differentiation of bone marrow stem cells were promoted on the RAM with osteoid-like stiffness, specifically on the oxidized RAM. The in vivo evidence revealed that nonoxidized RAM with osteoid-like stiffness upregulated osteogenic genes but prevented ingrowth of newly formed bone, leading to limited regeneration. Oxidized RAM with osteoid-like stiffness facilitated collagen synthesis, angiogenesis, and osteogenesis and induced robust bone formation, thereby significantly promoting maxillofacial regeneration. Overall, this study supported that in the stabilized microenvironment, oxidized RAM with osteoid-like stiffness offered requisite mechanical cues for osteogenesis and an appropriate degradation profile to facilitate bone formation. Combining the 3D-printed hydroxyapatite scaffold and oxidized RAM with osteoid-like stiffness may be an advantageous approach for maxillofacial regeneration.
Liver transplant recipients frequently develop acute kidney injury (AKI), but the predisposing factors and long-term consequences of AKI are not well understood. The aims of this study were to ...identify predisposing factors for early post-transplant AKI and the impact of AKI on patient and graft survival and to construct a model to predict AKI using clinical variables.
In this 5-year retrospective study, we analysed clinical and laboratory data from 424 liver transplant recipients from our centre.
By 72 h post-transplant, 221 patients (52%) had developed AKI according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria. Predisposing factors for development of AKI were female sex, weight (>100 kg), severity of liver disease (Child–Pugh score), pre-existing diabetes mellitus, number of units of blood or fresh frozen plasma transfused during surgery, and non-alcoholic steatohepatitis as the aetiology of end-stage liver disease (P≤0.05). Notably, preoperative serum creatinine (SCr) was not a significant predisposing factor. After fitting a forward stepwise regression model, female sex, weight >100 kg, high Child–Pugh score, and diabetes remained significantly associated with the development of AKI within 72 h (P≤0.05). The area under the receiver operator characteristic curve for the final model was 0.71. The incidence of new chronic kidney disease and requirement for dialysis at 3 months and 1 yr post-transplant were significantly higher among patients who developed AKI.
Development of AKI within the first 72 h after transplant impacted short-term and long-term graft survival.
There is accumulating anecdotal evidence that anosmia and dysgeusia are associated with the COVID-19 pandemic. To investigate their relationship to SARS-CoV2 infection, the American Academy of ...Otolaryngology-Head and Neck Surgery developed the COVID-19 Anosmia Reporting Tool for Clinicians for the basis of this pilot study. This tool allows health care providers to confidentially submit cases of anosmia and dysgeusia related to COVID-19. We analyzed the first 237 entries, which revealed that anosmia was noted in 73% of patients prior to COVID-19 diagnosis and was the initial symptom in 26.6%. Some improvement was noted in 27% of patients, with a mean time to improvement of 7.2 days in this group (85% of this group improved within 10 days). Our findings suggest that anomia can be a presenting symptom of COVID-19, consistent with other emerging international reports. Anosmia may be critical in timely identification of individuals infected with SARS-CoV2 who may be unwittingly transmitting the virus.
Background and purpose
Elevated plasma total homocysteine level (tHcy) is associated with increased risk of dementia via increased white matter changes or reduction in cortical volume. Whether tHcy ...has an independent impact on regional perfusion and if it can predict a more rapid cognitive decline in mild Alzheimer dementia (AD) warrants investigation.
Methods
Eighty AD patients with a clinical dementia rating of 1 were enrolled. Their Cognitive Ability Screening Instrument (CASI) scores on enrolment and after 1 year of follow‐up as well as their perfusion index (PI) from single photon emission computed tomography upon enrolment were analyzed.
Results
In cross‐sectional analysis, elevated tHcy was associated with lower frontal PI independent of cerebrovascular risk factors (β = −0.35, P = 0.009). The CASI scores correlated with temporo‐parietal PI (Pearson r range 0.3–0.39, P < 0.01) but not with tHcy or frontal PI. By longitudinal analysis, only tHcy level was related to a more rapid cognitive decline (odds ratio for executive function score 1.82; odds ratio for total CASI score 1.74).
Conclusions
Cognitive performance in mild AD can be reflected by hypo‐perfusion of the temporo‐parietal region while frontal hypo‐perfusion may be mediated by tHcy. tHcy level is an independent risk factor for rapid cognitive decline, especially in the executive function.
Direct solar-powered production of value-added chemicals from CO2 and H2O, a process that mimics natural photosynthesis, is of fundamental and practical interest. In natural photosynthesis, CO2 is ...first reduced to common biochemical building blocks using solar energy, which are subsequently used for the synthesis of the complex mixture of molecular products that form biomass. Here we report an artificial photosynthetic scheme that functions via a similar two-step process by developing a biocompatible light-capturing nanowire array that enables a direct interface with microbial systems. As a proof of principle, we demonstrate that a hybrid semiconductor nanowire-bacteria system can reduce CO2 at neutral pH to a wide array of chemical targets, such as fuels, polymers, and complex pharmaceutical precursors, using only solar energy input. The high-surface-area silicon nanowire array harvests light energy to provide reducing equivalents to the anaerobic bacterium, Sporomusa ovata, for the photoelectrochemical production of acetic acid under aerobic conditions (21% O2) with low overpotential (η < 200 mV), high Faradaic efficiency (up to 90%), and long-term stability (up to 200 h). The resulting acetate (∼6 g/L) can be activated to acetyl coenzyme A (acetyl-CoA) by genetically engineered Escherichia coli and used as a building block for a variety of value-added chemicals, such as n-butanol, polyhydroxybutyrate (PHB) polymer, and three different isoprenoid natural products. As such, interfacing biocompatible solid-state nanodevices with living systems provides a starting point for developing a programmable system of chemical synthesis entirely powered by sunlight.
Summary
Background
Cirrhotic patients admitted to intensive care units (ICUs) have high mortality rates. The Chronic Liver Failure–Sequential Organ Failure Assessment (CLIF‐SOFA) score, a modified ...Sequential Organ Failure Assessment (SOFA) score, is a newly developed scoring system exclusively for patients with end‐stage liver disease.
Aim
To externally validate the efficacy of the CLIF‐SOFA score and evaluate other scoring systems for 6‐month mortality in critically ill cirrhotic patients.
Methods
This study prospectively recorded and analysed the data for 30 demographical parameters and some clinical characteristic variables on day 1 of 250 cirrhotic patients admitted to a 10‐bed specialised hepatogastroenterology ICU in a 2000‐bed tertiary care referral hospital during the period from September 2010 to August 2013.
Results
The overall in‐hospital and 6‐month mortality rate were 58.8% (147/250) and 78.0% (195/250), respectively. Liver diseases were mostly attributed to hepatitis B virus infection (32%). Multiple Cox logistic regression hazard analysis revealed that Glasgow coma scale, both the CLIF‐SOFA and Acute Physiology and Chronic Health Evaluation III (ACPACHE III) scores determined on the first day of ICU admission were independent predictors of 6‐month mortality. Analysis of the area under the receiver operating characteristic curve revealed that the CLIF‐SOFA score had the best discriminatory power (0.900 ± 0.020). Moreover, the cumulative 6‐month survival rates differed significantly for patients with a CLIF‐SOFA score ≤11 and those with a CLIF‐SOFA score >11 on the ICU admission day.
Conclusion
Both CLIF‐SOFA and APACHE III scores are excellent prognosis evaluation tools for critically ill cirrhotic patients.
We estimate the 21 cm radio background from accretion onto the first intermediate-mass black holes between z 30 and z 16. Combining potentially optimistic, but plausible, scenarios for black hole ...formation and growth with empirical correlations between luminosity and radio emission observed in low-redshift active galactic nuclei, we find that a model of black holes forming in molecular cooling halos is able to produce a 21 cm background that exceeds the cosmic microwave background (CMB) at z 17, though models involving larger halo masses are not entirely excluded. Such a background could explain the surprisingly large amplitude of the 21 cm absorption feature recently reported by the EDGES collaboration. Such black holes would also produce significant X-ray emission and contribute to the 0.5-2 keV soft X-ray background at the level of 10−13-10−12 erg s−1 cm−2 deg−2, consistent with existing constraints. In order to avoid heating the intergalactic medium (IGM) over the EDGES trough, these black holes would need to be obscured by hydrogen column depths of NH ∼ 5 × 1023 cm−2. Such black holes would avoid violating constraints on the CMB optical depth from Planck if their UV photon escape fractions were below fesc 0.1, which would be a natural result of NH ∼ 5 × 1023 cm−2 being imposed by an unheated IGM.
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