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Microbiome Mar 2023Arctic snowpack microbial communities are continually subject to dynamic chemical and microbial input from the atmosphere. As such, the factors that contribute to...
BACKGROUND
Arctic snowpack microbial communities are continually subject to dynamic chemical and microbial input from the atmosphere. As such, the factors that contribute to structuring their microbial communities are complex and have yet to be completely resolved. These snowpack communities can be used to evaluate whether they fit niche-based or neutral assembly theories.
METHODS
We sampled snow from 22 glacier sites on 7 glaciers across Svalbard in April during the maximum snow accumulation period and prior to the melt period to evaluate the factors that drive snowpack metataxonomy. These snowpacks were seasonal, accumulating in early winter on bare ice and firn and completely melting out in autumn. Using a Bayesian fitting strategy to evaluate Hubbell's Unified Neutral Theory of Biodiversity at multiple sites, we tested for neutrality and defined immigration rates at different taxonomic levels. Bacterial abundance and diversity were measured and the amount of potential ice-nucleating bacteria was calculated. The chemical composition (anions, cations, organic acids) and particulate impurity load (elemental and organic carbon) of the winter and spring snowpack were also characterized. We used these data in addition to geographical information to assess possible niche-based effects on snow microbial communities using multivariate and variable partitioning analysis.
RESULTS
While certain taxonomic signals were found to fit the neutral assembly model, clear evidence of niche-based selection was observed at most sites. Inorganic chemistry was not linked directly to diversity, but helped to identify predominant colonization sources and predict microbial abundance, which was tightly linked to sea spray. Organic acids were the most significant predictors of microbial diversity. At low organic acid concentrations, the snow microbial structure represented the seeding community closely, and evolved away from it at higher organic acid concentrations, with concomitant increases in bacterial numbers.
CONCLUSIONS
These results indicate that environmental selection plays a significant role in structuring snow microbial communities and that future studies should focus on activity and growth. Video Abstract.
Topics: Bayes Theorem; Ice Cover; Seasons; Bacteria; Biodiversity
PubMed: 36864462
DOI: 10.1186/s40168-023-01473-6 -
Journal of Personalized Medicine Sep 2022Delayed graft function is a frequent complication of kidney transplantation that requires dialysis in the first week posttransplant. (Review)
Review
BACKGROUND
Delayed graft function is a frequent complication of kidney transplantation that requires dialysis in the first week posttransplant.
MATERIALS AND METHODS
We searched for the most relevant articles in the National Institutes of Health library of medicine, as well as in transplantation, pharmacologic, and nephrological journals.
RESULTS
The main factors that may influence the development of delayed graft function (DGF) are ischemia-reperfusion injury, the source and the quality of the donated kidney, and the clinical management of the recipient. The pathophysiology of ischemia-reperfusion injury is complex and involves kidney hypoxia related to the duration of warm and cold ischemia, as well as the harmful effects of blood reperfusion on tubular epithelial cells and endothelial cells. Ischemia-reperfusion injury is more frequent and severe in kidneys from deceased donors than in those from living donors. Of great importance is the quality and function of the donated kidney. Kidneys from living donors and those with normal function can provide better results. In the peri-operative management of the recipient, great attention should be paid to hemodynamic stability and blood pressure; nephrotoxic medicaments should be avoided. Over time, patients with DGF may present lower graft function and survival compared to transplant recipients without DGF. Maladaptation repair, mitochondrial dysfunction, and acute rejection may explain the worse long-term outcome in patients with DGF. Many different strategies meant to prevent DGF have been evaluated, but only prolonged perfusion of dopamine and hypothermic machine perfusion have proven to be of some benefit. Whenever possible, a preemptive transplant from living donor should be preferred.
PubMed: 36294695
DOI: 10.3390/jpm12101557 -
Nature Communications Dec 2022The development of electrocatalysts capable of efficient reduction of nitrate (NO) to ammonia (NH) is drawing increasing interest for the sake of low carbon emission and...
The development of electrocatalysts capable of efficient reduction of nitrate (NO) to ammonia (NH) is drawing increasing interest for the sake of low carbon emission and environmental protection. Herein, we present a CuCo bimetallic catalyst able to imitate the bifunctional nature of copper-type nitrite reductase, which could easily remove NO via the collaboration of two active centers. Indeed, Co acts as an electron/proton donating center, while Cu facilitates NO adsorption/association. The bio-inspired CuCo nanosheet electrocatalyst delivers a 100 ± 1% Faradaic efficiency at an ampere-level current density of 1035 mA cm at -0.2 V vs. Reversible Hydrogen Electrode. The NH production rate reaches a high activity of 4.8 mmol cm h (960 mmol g h). A mechanistic study, using electrochemical in situ Fourier transform infrared spectroscopy and shell-isolated nanoparticle enhanced Raman spectroscopy, reveals a strong synergy between Cu and Co, with Co sites promoting the hydrogenation of NO to NH via adsorbed *H species. The well-modulated coverage of adsorbed *H and *NO led simultaneously to high NH selectivity and yield.
Topics: Ammonia; Hydrogenation; Adsorption; Carbon; Nitrite Reductases
PubMed: 36550156
DOI: 10.1038/s41467-022-35533-6 -
Orthopaedics & Traumatology, Surgery &... Dec 2021The analysis of osteochondral lesions of talus (OLT) is currently mostly descriptive, not permitting an understanding of the different nosological frameworks of these...
INTRODUCTION
The analysis of osteochondral lesions of talus (OLT) is currently mostly descriptive, not permitting an understanding of the different nosological frameworks of these lesions. Better knowledge of the characteristics of patients with OLT should make it possible to optimize the surgical indications and anticipate the associated lesions, which should not be overlooked. The main objective of this study was, therefore, to assess the characteristics of patients with OLT, and to analyze the lesions encountered.
HYPOTHESIS
OLTs correspond to variable entities responding to specific treatments.
MATERIAL AND METHOD
This was a prospective multicenter descriptive study including all patients operated on for an OLT, aged between 15 and 65 years, across 10 French specialist centers. The demographic, clinical and radiological data of the patients were analyzed.
RESULTS
OLTs predominantly affect males and patients in their thirties. Two types of OLT should be distinguished: a lateral OLT; smaller and more superficial, most often presenting with painful instability, in the context of trauma, and a medial OLT; more frequent, wider and deeper.
DISCUSSION
Two nosological frameworks exist for OLTs, and correspond to precise surgical indications: medial lesions of more than 10mm and more than 5mm in depth, with isolated anteromedial pain and significant functional impairment, most often idiopathic, generally requiring treatment by osteochondral autografts. Lateral lesions less than 5mm in depth and less than 10mm, often superficial, following trauma or ankle laxity, associated with lateral ligament damage in one-third of cases, and a clinical presentation associated to instability and pain, requiring treatment most often by microfracture with associated ligament repair.
LEVEL OF EVIDENCE
III.
Topics: Adolescent; Adult; Aged; Cartilage, Articular; Humans; Intra-Articular Fractures; Joint Instability; Male; Middle Aged; Prospective Studies; Talus; Transplantation, Autologous; Treatment Outcome; Young Adult
PubMed: 34547540
DOI: 10.1016/j.otsr.2021.103068 -
Orthopaedics & Traumatology, Surgery &... Dec 2022There are presently 3 postoperative protocols after rotator cuff repair: strict immobilization, passive motion and early active motion. There is no consensus as to which... (Review)
Review
INTRODUCTION
There are presently 3 postoperative protocols after rotator cuff repair: strict immobilization, passive motion and early active motion. There is no consensus as to which is to be preferred. The aim of the present study was to conduct a network meta-analysis to determine whether one particular protocol shows advantages in terms of healing, motion, clinical scores and complications.
METHODS
A search of the PubMed, Embase and Central databases extracted all randomized controlled trials (RCTs) comparing at least 2 protocols. Eighteen RCTs were thus included, for a total 1704 patients (mean age, 58.1 years) and 1726 shoulders.
RESULTS
Strict immobilization was associated with lower flexion at 1 year than passive motion (mean difference, 2.66 [95% CI, 0.42-6.20]) and active motion (mean difference, 3.76 [95% CI, 0.17-7.80]). There were no differences between protocols for external rotation, healing at 1 year or Constant, ASES and STT scores in the short and medium terms. There was no difference in complications rate.
CONCLUSION
Early motion, whether passive or active, leads to greater flexion than does strict immobilization. No other differences were found between the protocols. Taking certain prognostic factors (lesion size, patient age, activity level, etc.) into account could guide specific rehabilitation according to type of lesion.
LEVEL OF EVIDENCE
I, network meta-analysis.
Topics: Humans; Middle Aged; Rotator Cuff; Rotator Cuff Injuries; Arthroscopy; Network Meta-Analysis; Treatment Outcome; Range of Motion, Articular; Meta-Analysis as Topic
PubMed: 36152940
DOI: 10.1016/j.otsr.2022.103418 -
Biology Jul 2021Many separate fields and practices nowadays consider microbes as part of their legitimate focus. Therefore, microbiome studies may act as unexpected unifying forces... (Review)
Review
Many separate fields and practices nowadays consider microbes as part of their legitimate focus. Therefore, microbiome studies may act as unexpected unifying forces across very different disciplines. Here, we summarize how microbiomes appear as novel major biological players, offer new artistic frontiers, new uses from medicine to laws, and inspire novel ontologies. We identify several convergent emerging themes across ecosystem studies, microbial and evolutionary ecology, arts, medicine, forensic analyses, law and philosophy of science, as well as some outstanding issues raised by microbiome studies across these disciplines and practices. An 'epistemic revolution induced by microbiome studies' seems to be ongoing, characterized by four features: (i) an ecologization of pre-existing concepts within disciplines, (ii) a growing interest in systemic analyses of the investigated or represented phenomena and a greater focus on interactions as their root causes, (iii) the intent to use openly multi-scalar interaction networks as an explanatory framework to investigate phenomena to acknowledge the causal effects of microbiomes, (iv) a reconceptualization of the usual definitions of which individuals are worth considering as an explanans or as an explanandum by a given field, which result in a fifth strong trend, namely (v) a de-anthropocentrification of our perception of the world.
PubMed: 34356506
DOI: 10.3390/biology10070651 -
Journal of Clinical Medicine Feb 2023Despite significant improvements of renal and obstetrical management, pregnancies in women with glomerular diseases and with lupus nephritis continue to be associated... (Review)
Review
Despite significant improvements of renal and obstetrical management, pregnancies in women with glomerular diseases and with lupus nephritis continue to be associated with increased complications both for the mother and the fetus as compared to those of pregnancies in healthy women. To reduce the risk of these complications, planning pregnancy in a phase of stable remission of the underlining disease is necessary. A kidney biopsy is an important event in any phase of pregnancy. A kidney biopsy can be of help during counselling before pregnancy in cases of incomplete remission of the renal manifestations. In these situations, histological data may differentiate active lesions that require the reinforcement of therapy from chronic irreversible lesions that may increase the risk of complications. In pregnant women, a kidney biopsy can identify new-onset systemic lupus erythematous (SLE) and necrotizing or primitive glomerular diseases and distinguish them from other, more common complications. Increasing proteinuria, hypertension, and the deterioration of kidney function during pregnancy may be either due to a reactivation of the underlying disease or to pre-eclampsia. The results of the kidney biopsy suggest the need to initiate an appropriate treatment, allowing the progression of the pregnancy and the fetal viability or the anticipation of delivery. Data from the literature suggest avoiding a kidney biopsy beyond 28 weeks of gestation to minimize the risks associated with the procedure vs. the risk of preterm delivery. In case of the persistence of renal manifestations after delivery in women with a diagnosis of pre-eclampsia, a renal kidney assessment allows the final diagnosis and guides the therapy.
PubMed: 36902621
DOI: 10.3390/jcm12051834 -
Frontiers in Microbiology 2020We investigated the interactions of air and snow over one entire winter accumulation period as well as the importance of chemical markers in a pristine free-tropospheric...
We investigated the interactions of air and snow over one entire winter accumulation period as well as the importance of chemical markers in a pristine free-tropospheric environment to explain variation in a microbiological dataset. To overcome the limitations of short term bioaerosol sampling, we sampled the atmosphere continuously onto quartzfiber air filters using a DIGITEL high volume PM10 sampler. The bacterial and fungal communities, sequenced using Illumina MiSeq, as well as the chemical components of the atmosphere were compared to those of a late season snow profile. Results reveal strong dynamics in the composition of bacterial and fungal communities in air and snow. In fall the two compartments were similar, suggesting a strong interaction between them. The overlap diminished as the season progressed due to an evolution within the snowpack throughout winter and spring. Certain bacterial and fungal genera were only detected in air samples, which implies that a distinct air microbiome might exist. These organisms are likely not incorporated in clouds and thus not precipitated or scavenged in snow. Although snow appears to be seeded by the atmosphere, both air and snow showed differing bacterial and fungal communities and chemical composition. Season and alpha diversity were major drivers for microbial variability in snow and air, and only a few chemical markers were identified as important in explaining microbial diversity. Air microbial community variation was more related to chemical markers than snow microbial composition. For air microbial communities Cl, TC/OC, SO , Mg, and Fe/Al, all compounds related to dust or anthropogenic activities, were identified as related to bacterial variability while dust related Ca was significant in snow. The only common driver for snow and air was SO , a tracer for anthropogenic sources. The occurrence of chemical compounds was coupled with boundary layer injections in the free troposphere (FT). Boundary layer injections also caused the observed variations in community composition and chemistry between the two compartments. Long-term monitoring is required for a more valid insight in post-depositional selection in snow.
PubMed: 32508790
DOI: 10.3389/fmicb.2020.00980 -
Biomaterials Dec 2022In optical devices such as camera or microscope, an aperture is used to regulate light intensity for imaging. Here we report the discovery and construction of a durable...
In optical devices such as camera or microscope, an aperture is used to regulate light intensity for imaging. Here we report the discovery and construction of a durable bio-aperture at nanometerscale that can regulate current at the pico-ampere scale. The nano-aperture is made of 12 identical protein subunits that form a 3.6-nm channel with a shutter and "one-way traffic" property. This shutter responds to electrical potential differences across the aperture and can be turned off for double stranded DNA translocation. This voltage enables directional control, and three-step regulation for opening and closing. The nano-aperture was constructed in vitro and purified into homogeneity. The aperture was stable at pH2-12, and a temperature of -85C-60C. When an electrical potential was held, three reproducible discrete steps of current flowing through the channel were recorded. Each step reduced 32% of the channel dimension evident by the reduction of the measured current flowing through the aperture. The current change is due to the change of the resistance of aperture size. The transition between these three distinct steps and the direction of the current was controlled via the polarity of the voltage applied across the aperture. When the C-terminal of the aperture was fused to an antigen, the antibody and antigen interaction resulted in a 32% reduction of the channel size. This phenomenon was used for disease diagnosis since the incubation of the antigen-nano-aperture with a specific cancer antibody resulted in a change of 32% of current. The purified truncated cone-shape aperture automatically self-assembled efficiently into a sheet of the tetragonal array via head-to-tail self-interaction. The nano-aperture discovery with a controllable shutter, discrete-step current regulation, formation of tetragonal sheet, and one-way current traffic provides a nanoscale electrical circuit rectifier for nanodevices and disease diagnosis.
Topics: Biomimetics; DNA
PubMed: 36356474
DOI: 10.1016/j.biomaterials.2022.121863 -
Orthopaedics & Traumatology, Surgery &... Dec 2018Ultrasound (US) imaging is an efficient, easy to use and inexpensive tool allowing for facilitated diagnosis and management of the painful shoulder. It remains primarily... (Review)
Review
Ultrasound (US) imaging is an efficient, easy to use and inexpensive tool allowing for facilitated diagnosis and management of the painful shoulder. It remains primarily used by radiologists and rheumatologists, despite having shown excellent diagnostic accuracy when used by different medical specialities in their office-based consultation. It also has advantages over other imaging modalities in the evaluation of the postoperative shoulder for rotator cuff integrity and correct anchor and suture placement, as well as rotator cuff analysis following arthroplasty. Integration of US imaging into the orthopaedic surgeon's toolbox can be aided by a basic understanding of US principles, accompanied by a guide outlining basic techniques for evaluation of the healthy, pathological and postoperative shoulder as well as US-guided treatment possibilities.
Topics: Humans; Orthopedics; Postoperative Period; Rotator Cuff; Shoulder Injuries; Shoulder Joint; Shoulder Pain; Ultrasonography
PubMed: 30107274
DOI: 10.1016/j.otsr.2018.07.011