Downlink communication experiments with OSIRISv1 laser terminal onboard Flying Laptop satellite.

Downlink measurement campaigns from the optical downlink terminal OSIRISv1 onboard the LEO satellite Flying Laptop were carried out with the French Observatoire de la Côte d'Azur and with two Optical Ground Stations of the German Aerospace Center. On/off keyed data at 39 Mb/s were modulated on the laser signal, and according telecom reception was performed by the ground stations. The pointing of the laser terminal was achieved by open-loop body pointing of the satellite orientation, with its star sensor as attitude control signal. We report here on the measurements and investigations of the downlink signal and the data transmission.

RNA processing machineries in Archaea: the 5'-3' exoribonuclease aRNase J of the ß-CASP family is engaged specifically with the helicase ASH-Ski2 and the 3'-5' exoribonucleolytic RNA exosome machinery.

A network of RNA helicases, endoribonucleases and exoribonucleases regulates the quantity and quality of cellular RNAs. To date, mechanistic studies focussed on bacterial and eukaryal systems due to the challenge of identifying the main drivers of RNA decay and processing in Archaea. Here, our data support that aRNase J, a 5'-3' exoribonuclease of the ß-CASP family conserved in Euryarchaeota, engages specifically with a Ski2-like helicase and the RNA exosome to potentially exert control over RNA surveillance, at the vicinity of the ribosome. Proteomic landscapes and direct protein-protein interaction analyses, strengthened by comprehensive phylogenomic studies demonstrated that aRNase J interplay with ASH-Ski2 and a cap exosome subunit. Finally, Thermococcus barophilus whole-cell extract fractionation experiments provide evidences that an aRNase J/ASH-Ski2 complex might exist in vivo and hint at an association of aRNase J with the ribosome that is emphasised in absence of ASH-Ski2. Whilst aRNase J homologues are found among bacteria, the RNA exosome and the Ski2-like RNA helicase have eukaryotic homologues, underlining the mosaic aspect of archaeal RNA machines. Altogether, these results suggest a fundamental role of ß-CASP RNase/helicase complex in archaeal RNA metabolism.

Physical and functional interplay between PCNA DNA clamp and Mre11-Rad50 complex from the archaeon Pyrococcus furiosus.

Several archaeal species prevalent in extreme environments are particularly exposed to factors likely to cause DNA damages. These include hyperthermophilic archaea (HA), living at temperatures >70°C, which arguably have efficient strategies and robust genome guardians to repair DNA damage threatening their genome integrity. In contrast to Eukarya and other archaea, homologous recombination appears to be a vital pathway in HA, and the Mre11-Rad50 complex exerts a broad influence on the initiation of this DNA damage response process. In a previous study, we identified a physical association between the Proliferating Cell Nuclear Antigen (PCNA) and the Mre11-Rad50 (MR) complex. Here, by performing co-immunoprecipitation and SPR analyses, we identified a short motif in the C- terminal portion of Pyrococcus furiosus Mre11 involved in the interaction with PCNA. Through this work, we revealed a PCNA-interaction motif corresponding to a variation on the PIP motif theme which is conserved among Mre11 sequences of Thermococcale species. Additionally, we demonstrated functional interplay in vitro between P. furiosus PCNA and MR enzymatic functions in the DNA end resection process. At physiological ionic strength, PCNA stimulates MR nuclease activities for DNA end resection and promotes an endonucleolytic incision proximal to the 5' strand of double strand DNA break.

Archaeal ß-CASP ribonucleases of the aCPSF1 family are orthologs of the eukaryal CPSF-73 factor.

Bacterial RNase J and eukaryal cleavage and polyadenylation specificity factor (CPSF-73) are members of the ß-CASP family of ribonucleases involved in mRNA processing and degradation. Here we report an in-depth phylogenomic analysis that delineates aRNase J and archaeal CPSF (aCPSF) as distinct orthologous groups and establishes their repartition in 110 archaeal genomes. The aCPSF1 subgroup, which has been inherited vertically and is strictly conserved, is characterized by an N-terminal extension with two K homology (KH) domains and a C-terminal motif involved in dimerization of the holoenzyme. Pab-aCPSF1 (Pyrococcus abyssi homolog) has an endoribonucleolytic activity that preferentially cleaves at single-stranded CA dinucleotides and a 5'-3' exoribonucleolytic activity that acts on 5' monophosphate substrates. These activities are the same as described for the eukaryotic cleavage and polyadenylation factor, CPSF-73, when engaged in the CPSF complex. The N-terminal KH domains are important for endoribonucleolytic cleavage at certain specific sites and the formation of stable high molecular weight ribonucleoprotein complexes. Dimerization of Pab-aCPSF is important for exoribonucleolytic activity and RNA binding. Altogether, our results suggest that aCPSF1 performs an essential function and that an enzyme with similar activities was present in the last common ancestor of Archaea and Eukarya.

Cbp1 and Cren7 form chromatin-like structures that ensure efficient transcription of long CRISPR arrays.

CRISPR arrays form the physical memory of CRISPR adaptive immune systems by incorporating foreign DNA as spacers that are often AT-rich and derived from viruses. As promoter elements such as the TATA-box are AT-rich, CRISPR arrays are prone to harbouring cryptic promoters. Sulfolobales harbour extremely long CRISPR arrays spanning several kilobases, a feature that is accompanied by the CRISPR-specific transcription factor Cbp1. Aberrant Cbp1 expression modulates CRISPR array transcription, but the molecular mechanisms underlying this regulation are unknown. Here, we characterise the genome-wide Cbp1 binding at nucleotide resolution and characterise the binding motifs on distinct CRISPR arrays, as well as on unexpected non-canonical binding sites associated with transposons. Cbp1 recruits Cren7 forming together 'chimeric' chromatin-like structures at CRISPR arrays. We dissect Cbp1 function in vitro and in vivo and show that the third helix-turn-helix domain is responsible for Cren7 recruitment, and that Cbp1-Cren7 chromatinization plays a dual role in the transcription of CRISPR arrays. It suppresses spurious transcription from cryptic promoters within CRISPR arrays but enhances CRISPR RNA transcription directed from their cognate promoters in their leader region. Our results show that Cbp1-Cren7 chromatinization drives the productive expression of long CRISPR arrays.

Evolutionary and functional insights into the Ski2-like helicase family in Archaea: a comparison of Thermococcales ASH-Ski2 and Hel308 activities.

RNA helicases perform essential housekeeping and regulatory functions in all domains of life by binding and unwinding RNA molecules. The Ski2-like proteins are primordial helicases that play an active role in eukaryotic RNA homeostasis pathways, with multiple homologs having specialized functions. The significance of the expansion and diversity of Ski2-like proteins in Archaea, the third domain of life, has not yet been established. Here, by studying the phylogenetic diversity of Ski2-like helicases among archaeal genomes and the enzymatic activities of those in Thermococcales, we provide further evidence of the function of this protein family in archaeal metabolism of nucleic acids. We show that, in the course of evolution, ASH-Ski2 and Hel308-Ski2, the two main groups of Ski2-like proteins, have diverged in their biological functions. Whereas Hel308 has been shown to mainly act on DNA, we show that ASH-Ski2, previously described to be associated with the 5'-3' aRNase J exonuclease, acts on RNA by supporting an efficient annealing activity, but also an RNA unwinding with a 3'-5' polarity. To gain insights into the function of Ski2, we also analyse the transcriptome of Thermococcus barophilus ΔASH-Ski2 mutant strain and provide evidence of the importance of ASH-Ski2 in cellular metabolism pathways related to translation.

A pilot randomised controlled trial exploring the feasibility and efficacy of a human-AI sleep coaching model for improving sleep among university students.

Objective: Sleep quality is a crucial concern, particularly among youth. The integration of health coaching with question-answering (QA) systems presents the potential to foster behavioural changes and enhance health outcomes. This study proposes a novel human-AI sleep coaching model, combining health coaching by peers and a QA system, and assesses its feasibility and efficacy in improving university students' sleep quality. Methods: In a four-week unblinded pilot randomised controlled trial, 59 university students (mean age: 21.9; 64% males) were randomly assigned to the intervention (health coaching and QA system; n = 30) or the control conditions (QA system; n = 29). Outcomes included efficacy of the intervention on sleep quality (Pittsburgh Sleep Quality Index; PSQI), objective and self-reported sleep measures (obtained from Fitbit and sleep diaries) and feasibility of the study procedures and the intervention. Results: Analysis revealed no significant differences in sleep quality (PSQI) between intervention and control groups (adjusted mean difference = -0.51, 95% CI: [-1.55-0.77], p = 0.40). The intervention group demonstrated significant improvements in Fitbit measures of total sleep time (adjusted mean difference = 32.5, 95% CI: [5.9-59.1], p = 0.02) and time in bed (adjusted mean difference = 32.3, 95% CI: [2.7-61.9], p = 0.03) compared to the control group, although other sleep measures were insignificant. Adherence was high, with the majority of the intervention group attending all health coaching sessions. Most participants completed baseline and post-intervention self-report measures, all diary entries, and consistently wore Fitbits during sleep. Conclusions: The proposed model showed improvements in specific sleep measures for university students and the feasibility of the study procedures and intervention. Future research may extend the intervention period to see substantive sleep quality improvements.

Two-mode interference measurement for nanometer accuracy absolute ranging.

We demonstrate a laser ranging scheme that uses a high-frequency modulated beam to achieve subnanometer precision by the combined use of interferometric and time-of-flight measurements. We first describe how the absolute distance is extracted from a two-mode interference signal. In particular, we show that the signal, which presents both optical and synthetic wavelength scales, allows one to achieve nanometer-scale accuracy, despite the significant long-term phase drifts in the 20 GHz detection chains. We present results obtained with the telemeter implemented for a distance of about four meters, obtained by folding the laser beam path to the target.

Comparison of In-Hospital Outcomes of Surgical Stabilization of Rib Fractures with Nonsurgical Management: A Multicenter, Prospective, Cohort Study.

Background: Evidence for the efficacy of surgical stabilization of rib fractures in patients with rib fractures is controversial. Objective: We aim to compare the clinical outcomes of surgical rib fixation for rib fracture with non-operative treatment. Methods: Our institutional database from three general hospitals (Viet Duc Hospital, Viet Tiep Friendship Hospital & Cho Ray Hospital) was queried to identify patients with flail chest treated with locked plate fixation between December 2021 and February 2023. A medical record review for demographic, injury, hospital, and surgical data was also retrospectively performed for all patients. Characteristics and outcomes of the patients receiving the surgical rib fixation for rib fracture were compared with those without surgery. Results: A total of 166 patients with thoracic trauma were included. The majority of patients were male, and the age range was from 18 to 80 years old, with a mean age of 51.6 years. 52 (31.3%) underwent surgical stabilization of rib fractures (SSRF). The highest combined injuries were limb injuries, followed by traumatic brain injury, and maxillofacial trauma. While 1 patient died in the non-surgical group, there was no significant difference in the mortality between the two groups. The surgical group had a slightly shorter hospital stay than the non-surgical group (8.6 days vs. 10.0 days, p-value: 0.038). SSRF group tended toward a lower incidence of pneumonia compared to the non-surgical group (SSRF: 3.8% vs. non-surgical: 7%), but this difference was not statistically significant (p-value: 0.426). SSRF group also had a lower incidence of tracheostomy than the non-operative group (SSRF: 0% vs. non-surgical: 1.8%, p-value: 0.337). Conclusion: Operative fixation of a rib fracture in trauma patients resulted in a lower incidence of pneumonia, fewer days of mechanical ventilation, and a shorter hospital stay compared to non-operative treatment group.

A digital microfluidic droplet generator produces self-assembled supramolecular nanoparticles for targeted cell imaging.

Controlling the size distribution of polymer-based nanoparticles is a challenging task due to their flexible core and surface structures. To accomplish such as task requires very precise control at the molecular level. Here we demonstrate a new approach whereby uniform-sized supramolecular nanoparticles (SNPs) can be reliably generated using a digital microfluidic droplet generator (DMDG) chip. A microfluidic environment enabled precise control over the processing parameters, and therefore high batch-to-batch reproducibility and robust production of SNPs with a very narrow size distribution could be realized. Digitally adjustment of the mixing ratios of the building blocks on the DMDG chip allowed us to rapidly scan a variety of synthesis conditions without consuming significant amounts of reagents. Nearly uniform SNPs with sizes ranging from 35 to 350 nm were obtained and characterized by transmission electron microscopy and dynamic light scattering. In addition, we could fine-tune the surface chemistry of the SNPs by incorporating an additional building block functionalized with specific ligands for targeting cells. The sizes and surface properties of these SNPs correlated strongly with their cell uptake efficiencies. This study showed a feasible method for microfluidic-assisted SNP production and provided a great means for preparing size-controlled SNPs with desired surface ligand coverage.

Successful Aneurysmorrhaphy for a Giant Idiopathic Pulmonary Artery Aneurysm.

Idiopathic aneurysm of pulmonary artery is a rare disorder with unclear pathology and mechanism. The indications for its surgical treatment are not clear, especially in cases with normal pulmonary pressure. We report the case of a 64-year-old man with a giant idiopathic aneurysm of the pulmonary artery (max diameter 97.3 mm). The patient successfully underwent surgical treatment with the aneurysmorrhaphy in our Department of Cardiovascular and Thoracic Surgery. The patient was extubated successfully within 6 hours of the operation and discharged hospital after 10 days. In cases with giant aneurysm of the pulmonary artery, the aneurysmorrhaphy may be considered as a safe and feasible choice.

Surgical pulmonary embolectomy in a multi-trauma patient: One-center experience in the resource-limited setting.

Pulmonary embolism, a serious complication after trauma, may cause sudden death. We discuss an unusual case of 65-year-old woman who had traffic accident with liver injury and open fracture of both tibia and fibula on the right side. She was diagnosed with massive pulmonary embolism on the second day after accident and successfully underwent emergency surgical embolectomy from bilateral pulmonary arteries. There were no postoperative complications. The patient's good state of health was recorded after 13 months of surgery. Surgical pulmonary embolectomy for such a multi-trauma patient provides valuable experience not only for our institution but also for the countries having similar resource-limited conditions.

The cutting edge of archaeal transcription.

The archaeal RNA polymerase (RNAP) is a double-psi ß-barrel enzyme closely related to eukaryotic RNAPII in terms of subunit composition and architecture, promoter elements and basal transcription factors required for the initiation and elongation phase of transcription. Understanding archaeal transcription is, therefore, key to delineate the universally conserved fundamental mechanisms of transcription as well as the evolution of the archaeo-eukaryotic transcription machineries. The dynamic interplay between RNAP subunits, transcription factors and nucleic acids dictates the activity of RNAP and ultimately gene expression. This review focusses on recent progress in our understanding of (i) the structure, function and molecular mechanisms of known and less characterized factors including Elf1 (Elongation factor 1), NusA (N-utilization substance A), TFS4, RIP and Eta, and (ii) their evolution and phylogenetic distribution across the expanding tree of Archaea.

Tips and tricks to probe the RNA-degrading activities of hyperthermophilic archaeal ß-CASP ribonucleases.

The importance of ribonucleases in posttranscriptional control of gene expression has been established in Eukarya and Bacteria for over a decade. However, this process has been overlooked in Archaea, which are of universal importance to elucidate fundamental biological mechanisms and to study the evolution of life on Earth. Very few ribonucleolytic activities have been reported in Archaea, and RNA metabolism pathways wait to be described. Recently we have identified two major groups of archaeal ribonucleases, aCPSF1 and aRNase J, which are members of the ß-CASP metallo-ß-lactamase family. Here, we describe in vitro methods to characterize the endo- and exoribonucleolytic activities of hyperthermophilic archaeal ß-CASP ribonucleases. The use of various labeled RNA substrates allows defining the specificity of RNA cleavage and the directionality of the exoribonucleolytic trimming activity of the archaeal enzymes which work at high temperature. Elucidating in vitro ribonucleolytic activities is one step toward the understanding of the role of ß-CASP ribonucleases in RNA metabolism pathways in archaeal cells.

Universal RNA-degrading enzymes in Archaea: Prevalence, activities and functions of ß-CASP ribonucleases.

ß-CASP ribonucleases are widespread in all three domains of life. They catalyse both 5'-3' exoribonucleolytic RNA trimming and/or endoribonucleolytic RNA cleavage using a unique active site coordinated by two zinc ions. These fascinating enzymes have a key role in 3' end processing in Eukarya and in RNA decay and ribosomal RNA maturation in Bacteria. The recent recognition of ß-CASP ribonucleases as major players in Archaea is an important contribution towards identifying RNA-degrading enzymes in the third domain of life. Three ß-CASP orthologous groups, aCPSF1, aCPSF2, aCPSF1b, are closely related to the eukaryal CPSF73 termination factor and one, aRNase J, is ortholog of the bacterial RNase J. The endo- and 5'-3' exoribonucleolytic activities carried by archaeal ß-CASP enzymes are strictly conserved throughout archaeal phylogeny suggesting essential roles in maturation and/or degradation of RNA. The recent progress in understanding the prevalence, activities and functions of archaeal ß-CASP ribonucleases is the focus of this review. The current status of our understanding of RNA processing pathways in Archaea is covered in light of this new knowledge on ß-CASP ribonucleases.

Microwave-assisted one-pot synthesis of N-succinimidyl-4[ ¹8F]fluorobenzoate ([¹8F]SFB).

Biomolecules, including peptides¹â»9, proteins¹°â»¹¹, and antibodies and their engineered fragments¹²â»¹4, are gaining importance as both potential therapeutics and molecular imaging agents. Notably, when labeled with positron-emitting radioisotopes (e.g., Cu-64, Ga-68, or F-18), they can be used as probes for targeted imaging of many physiological and pathological processes.¹5⁻¹8 Therefore, significant effort has devoted to the synthesis and exploration of ¹8F-labeled biomolecules. Although there are elegant examples of the direct ¹8F-labeling of peptides,¹9⁻²² the harsh reaction conditions (i.e., organic solvent, extreme pH, high temperature) associated with direct radiofluorination are usually incompatible with fragile protein samples. To date, therefore, the incorporation of radiolabeled prosthetic groups into biomolecules remains the method of choice.²³(,)²4 N-Succinimidyl-4-[¹8F]fluorobenzoate ([¹8F]SFB),²5⁻³7 a Bolton-Hunter type reagent that reacts with the primary amino groups of biomolecules, is a very versatile prosthetic group for the ¹8F-labeling of a wide spectrum of biological entities, in terms of its evident in vivo stability and high radiolabeling yield. After labeling with [¹8F]SFB, the resulting [F]fluorobenzoylated biomolecules could be explored as potential PET tracers for in vivo imaging studies.¹ Most [¹8F]SFB radiosyntheses described in the current literatures require two or even three reactors and multiple purifications by using either solid phase extraction (SPE) or high-performance liquid chromatography (HPLC). Such lengthy processes hamper its routine production and widespread applications in the radiolabeling of biomolecules. Although several module-assisted [¹8F]SFB syntheses have been reported²9⁻³²,4¹â»4² they are mainly based on complicated and lengthy procedures using costly commercially-available radiochemistry boxes (Table 1). Therefore, further simplification of the radiosynthesis of [¹8F]SFB using a low-cost setup would be very beneficial for its adaption to an automated process. Herein, we report a concise preparation of [¹8F]SFB, based on a simplified one-pot microwave-assisted synthesis (Figure 1). Our approach does not require purification between steps or any aqueous reagents. In addition, microwave irradiation, which has been used in the syntheses of several PET tracers,³8⁻4¹ can gives higher RCYs and better selectivity than the corresponding thermal reactions or they provide similar yields in shorter reaction times.³8Most importantly, when labeling biomolecules, the time saved could be diverted to subsequent bioconjugation or PET imaging step. ²8(,)4³The novelty of our improved [¹8F]SFB synthesis is two-fold: (1) the anhydrous deprotection strategy requires no purification of intermediate(s) between each step and (2) the microwave-assisted radiochemical transformations enable the rapid, reliable production of [¹8F]SFB.

Molecular Imaging Probe Development using Microfluidics.

In this manuscript, we review the latest advancement of microfluidics in molecular imaging probe development. Due to increasing needs for medical imaging, high demand for many types of molecular imaging probes will have to be met by exploiting novel chemistry/radiochemistry and engineering technologies to improve the production and development of suitable probes. The microfluidic-based probe synthesis is currently attracting a great deal of interest because of their potential to deliver many advantages over conventional systems. Numerous chemical reactions have been successfully performed in micro-reactors and the results convincingly demonstrate with great benefits to aid synthetic procedures, such as purer products, higher yields, shorter reaction times compared to the corresponding batch/macroscale reactions, and more benign reaction conditions. Several 'proof-of-principle' examples of molecular imaging probe syntheses using microfluidics, along with basics of device architecture and operation, and their potential limitations are discussed here.