A dusty compact object bridging galaxies and quasars at cosmic dawn.

Understanding how super-massive black holes form and grow in the early Universe has become a major challenge1,2 since it was discovered that luminous quasars existed only 700 million years after the Big Bang3,4. Simulations indicate an evolutionary sequence of dust-reddened quasars emerging from heavily dust-obscured starbursts that then transition to unobscured luminous quasars by expelling gas and dust5. Although the last phase has been identified out to a redshift of 7.6 (ref. 6), a transitioning quasar has not been found at similar redshifts owing to their faintness at optical and near-infrared wavelengths. Here we report observations of an ultraviolet compact object, GNz7q, associated with a dust-enshrouded starburst at a redshift of 7.1899 ± 0.0005. The host galaxy is more luminous in dust emission than any other known object at this epoch, forming 1,600 solar masses of stars per year within a central radius of 480 parsec. A red point source in the far-ultraviolet is identified in deep, high-resolution imaging and slitless spectroscopy. GNz7q is extremely faint in X-rays, which indicates the emergence of a uniquely ultraviolet compact star-forming region or a Compton-thick super-Eddington black-hole accretion disk at the dusty starburst core. In the latter case, the observed properties are consistent with predictions from cosmological simulations7 and suggest that GNz7q is an antecedent to unobscured luminous quasars at later epochs.

An extremely young massive clump forming by gravitational collapse in a primordial galaxy.

When cosmic star formation history reaches a peak (at about redshift z ≈ 2), galaxies vigorously fed by cosmic reservoirs are dominated by gas and contain massive star-forming clumps, which are thought to form by violent gravitational instabilities in highly turbulent gas-rich disks. However, a clump formation event has not yet been observed, and it is debated whether clumps can survive energetic feedback from young stars, and afterwards migrate inwards to form galaxy bulges. Here we report the spatially resolved spectroscopy of a bright off-nuclear emission line region in a galaxy at z = 1.987. Although this region dominates star formation in the galaxy disk, its stellar continuum remains undetected in deep imaging, revealing an extremely young (less than ten million years old) massive clump, forming through the gravitational collapse of more than one billion solar masses of gas. Gas consumption in this young clump is more than tenfold faster than in the host galaxy, displaying high star-formation efficiency during this phase, in agreement with our hydrodynamic simulations. The frequency of older clumps with similar masses, coupled with our initial estimate of their formation rate (about 2.5 per billion years), supports long lifetimes (about 500 million years), favouring models in which clumps survive feedback and grow the bulges of present-day galaxies.

Fluctuations of a membrane nanotube revealed by high-resolution force measurements.

Pulling membrane nanotubes from liposomes presents a powerful method to gain access to membrane mechanics. Here we extend classical optical tweezers studies to infer membrane nanotube dynamics with high spatial and temporal resolution. We first validate our force measurement setup by accurately measuring the bending modulus of EPC membrane in tube pulling experiments. Then we record the position signal of a trapped bead when it is connected, or not, to a tube. We derive the fluctuation spectrum of these signals and find that the presence of a membrane nanotube induces higher fluctuations, especially at low frequencies (10-1000 Hz). We analyse these spectra by taking into account the peristaltic modes of nanotube fluctuations. This analysis provides a new experimental framework for a quantitative study of the fluctuations of nanotubular membrane structures that are present in living cells, and now classically used for in vitro biomimetic approaches.

Polyhydroxyalkanoate (PHA) production from sludge and municipal wastewater treatment.

Polyhydroxyalkanoates (PHAs) are biodegradable polyesters with comparable properties to some petroleum-based polyolefins. PHA production can be achieved in open, mixed microbial cultures and thereby coupled to wastewater and solid residual treatment. In this context, waste organic matter is utilised as a carbon source in activated sludge biological treatment for biopolymer synthesis. Within the EU project Routes, the feasibility of PHA production has been evaluated in processes for sludge treatment and volatile fatty acid (VFA) production and municipal wastewater treatment. This PHA production process is being investigated in four units: (i) wastewater treatment with enrichment and production of a functional biomass sustaining PHA storage capacity, (ii) acidogenic fermentation of sludge for VFA production, (iii) PHA accumulation from VFA-rich streams, and (iv) PHA recovery and characterisation. Laboratory- and pilot-scale studies demonstrated the feasibility of municipal wastewater and solid waste treatment alongside production of PHA-rich biomass. The PHA storage capacity of biomass selected under feast-famine with municipal wastewater has been increased up to 34% (g PHA g VSS(-1)) in batch accumulations with acetate during 20 h. VFAs obtained from waste activated sludge fermentation were found to be a suitable feedstock for PHA production.

Streamlined, single-step non-viral CRISPR-Cas9 knockout strategy enhances gene editing efficiency in primary human chondrocyte populations.

BACKGROUND: CRISPR-Cas9-based genome engineering represents a powerful therapeutic tool for cartilage tissue engineering and for understanding molecular pathways driving cartilage diseases. However, primary chondrocytes are difficult to transfect and rapidly dedifferentiate during monolayer (2D) cell culture, making the lengthy expansion of a single-cell-derived edited clonal population not feasible. For this reason, functional genetics studies focused on cartilage and rheumatic diseases have long been carried out in cellular models that poorly recapitulate the native molecular properties of human cartilaginous tissue (e.g., cell lines, induced pluripotent stem cells). Here, we set out to develop a non-viral CRISPR-Cas9, bulk-gene editing method suitable for chondrocyte populations from different cartilaginous sources. METHODS: We screened electroporation and lipid nanoparticles for ribonucleoprotein (RNP) delivery in primary polydactyly chondrocytes, and optimized RNP reagents assembly. We knocked out RELA (also known as p65), a subunit of the nuclear factor kappa B (NF-κB), in polydactyly chondrocytes and further characterized knockout (KO) cells with RT-qPCR and Western Blot. We tested RELA KO in chondrocytes from diverse cartilaginous sources and characterized their phenotype with RT-qPCR. We examined the chondrogenic potential of wild-type (WT) and KO cell pellets in presence and absence of interleukin-1ß (IL-1ß). RESULTS: We established electroporation as the optimal transfection technique for chondrocytes enhancing transfection and editing efficiency, while preserving high cell viability. We knocked out RELA with an unprecedented efficiency of ~90%, confirming lower inflammatory pathways activation upon IL-1ß stimulation compared to unedited cells. Our protocol could be easily transferred to primary human chondrocytes harvested from osteoarthritis (OA) patients, human FE002 chondroprogenitor cells, bovine chondrocytes, and a human chondrocyte cell line, achieving comparable mean RELA KO editing levels using the same protocol. All KO pellets from primary human chondrocytes retained chondrogenic ability equivalent to WT cells, and additionally displayed enhanced matrix retention under inflamed conditions. CONCLUSIONS: We showcased the applicability of our bulk gene editing method to develop effective autologous and allogeneic off-the-shelf gene therapies strategies and to enable functional genetics studies in human chondrocytes to unravel molecular mechanisms of cartilage diseases.

Hydrodynamic cavitation pre-treatment of urban waste: Integration with acidogenic fermentation, PHAs synthesis and anaerobic digestion processes.

Urban waste can be valorized within a biorefinery approach, producing platform chemicals, biopolymers and energy. In this framework, hydrodynamic cavitation (HC) is a promising pre-treatment for improving biodegradability due to its high effectiveness and low cost. This paper deals with the effect of HC pre-treatment on the acidogenic co-fermentation process of thickened sewage sludge from a WWTP and seasonal vegetable waste from a wholesale market. Specifically, HC was assessed by testing two sets of parameters (i.e., treatment time of 30 and 50 min; vacuum pressure 1.4 and 2.0 bar; applied power 8 and 17 kW) to determine its effectiveness as a pre-treatment of the mixture. The highest increase in sCOD (+83%) and VFAs (from 1.93 to 17.29 gCODVFA L-1) was gained after 50 min of cavitation. Fermentations were conducted with not cavitated and cavitated mixtures at 37 °C on 4 L reactors in batch mode, then switched to semi-continuous with OLR of 8 kgTVS m-3 d-1 and HRT of 5-6.6 d. Good VFAs concentrations (12.94-18.27 gCODVFA L-1) and yields (0.44-0.53 gCODVFA gVS(0)-1) were obtained, which could be enhanced by pre-treatment optimization and pH control. The organic acid rich broth obtained was then assessed as a substrate for PHAs storage by C. necator. It yielded 0.37 g g-1 of polyhydroxybutyrate, such biopolymer resulted to have analogous physicochemical characteristics of commercial equivalent. The only generated side-stream would be the solid-rich fraction of the fermented effluent, which valorization was assessed through BMP tests, showing a higher SGP of 0.42 Nm3 kgTVS-1 for the cavitated.

Elevated cerebrospinal fluid and plasma homocysteine levels in ALS.

BACKGROUND: High cerebrospinal fluid (CSF) and plasma levels of homocysteine (HC) have been reported in certain neurodegenerative disorders, such as Alzheimer's, Parkinson's diseases and, recently, amyotrophic lateral sclerosis (ALS). OBJECTIVES: To assay the CSF and plasma levels of HC in ALS patients and controls, and to evaluate the relationship between HC levels and clinical variables of the disease. METHODS: Cerebrospinal fluid from sixty-nine (M/F 1.87) and plasma from sixty-five ALS patients (M/F 1.83) were taken and stored at -80 degrees C until use. Controls (CSF = 55; plasma = 67) were patients admitted to our hospital for neurological disorders with no known relationship to HC changes. CSF and plasma from ALS patients and controls were obtained as a necessary step of the diagnostic workup. HC levels in CSF and plasma were assayed using a high performance liquid chromatograph (HPLC) and a fluorimeter detector. RESULTS: The median level of total HC in the CSF of ALS patients was 0.46( )microM, significantly higher than that of the controls (0.24 microM, +91.6%, P < 0.001). A similar trend was observed when HC was assayed in plasma (ALS, 12.4 microM vs. controls, 7.26 microM, +70.8%, P < 0.001). The CSF and plasma HC levels showed no relationship with the disease progression, age at onset, and the site of onset. CONCLUSIONS: Homocysteine is a biochemical marker in ALS, and it might be related to the pathophysiology of the disease.

Fluctuations of a membrane nanotube covered with an actin sleeve.

Many biological functions rely on the reshaping of cell membranes, in particular into nanotubes, which are covered in vivo by dynamic actin networks. Nanotubes are subject to thermal fluctuations, but the effect of these on cell functions is unknown. Here, we form nanotubes from liposomes using an optically trapped bead adhering to the liposome membrane. From the power spectral density of this bead, we study the nanotube fluctuations in the range of membrane tensions measured in vivo. We show that an actin sleeve covering the nanotube damps its high-frequency fluctuations because of the network viscoelasticity. Our work paves the way for further studies of the effect of nanotube fluctuations on cellular functions.

Actin modulates shape and mechanics of tubular membranes.

The actin cytoskeleton shapes cells and also organizes internal membranous compartments. In particular, it interacts with membranes for intracellular transport of material in mammalian cells, yeast, or plant cells. Tubular membrane intermediates, pulled along microtubule tracks, are formed during this process and destabilize into vesicles. While the role of actin in tubule destabilization through scission is suggested, literature also provides examples of actin-mediated stabilization of membranous structures. To directly address this apparent contradiction, we mimic the geometry of tubular intermediates with preformed membrane tubes. The growth of an actin sleeve at the tube surface is monitored spatiotemporally. Depending on network cohesiveness, actin is able to entirely stabilize or locally maintain membrane tubes under pulling. On a single tube, thicker portions correlate with the presence of actin. These structures relax over several minutes and may provide enough time and curvature geometries for other proteins to act on tube stability.

Complete long-term response to radiotherapy of gastric early-stage marginal zone lymphoma resistant to both anti-Helicobacter pylori antibiotics and chemotherapy.

BACKGROUND: The optimal approach to patients with gastric lymphoma of extranodal mucosa-associated lymphoid tissue (MALT) that resist to anti-Helicobacter pylori (HP) eradication therapy is still to be defined. PATIENTS AND METHODS: From January 1997 to December 2004, we observed 24 patients affected with newly diagnosed early-stage and HP-positive gastric lymphoma of the MALT type. Five of them resisted to oral anti-HP antibiotic regimens and to subsequent one (two patients) or two (three patients) chemotherapy regimens. Age ranged between 51 and 77 years (median 70); three were females. Translocation (11;18) was ascertained in one subject. They were admitted to local radiation therapy with a total dose of 30 Gy. RESULTS: All such resistant patients achieved complete remission after radiotherapy. No relapses were observed after 21, 45, 48, 52, and 67 months of uninterrupted follow-up. Early toxicity was very low and consisted of mild nausea. Late toxicity or secondary malignancy was not recorded so far. CONCLUSIONS: Radiotherapy proved to be effective and safe for early-stage HP-positive gastric extranodal lymphoma of MALT type that is resistant to anti-HP eradication antibiotics and to following chemotherapy. Radiotherapy might be suggested as principal salvage therapy after resistance to HP eradication, instead of chemotherapy.

Cerebrospinal fluid tau protein is not a biological marker in amyotrophic lateral sclerosis.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder leading to progressive motor neuron cell death. Etiopathogenesis is still imperfectly known and much effort have been undertaken to find a biological marker that could help in the early diagnosis and in the monitoring of disease progression. Cerebrospinal fluid (CSF) concentrations of tau, an axonal microtubule-associated protein, have been measured in ALS with levels found increased in some studies and unchanged in others. METHODS: Total CSF tau level was assayed in a population of ALS patients (n = 57) and controls (n = 110) using a specific ELISA method. RESULTS: No significant differences in the median CSF tau levels between ALS cases and controls were found [ALS: 126 pg/ml (78-222); controls: 112 pg/ml (71-188), P = ns]. In the ALS group, the bulbar-onset patients showed increased CSF tau levels as compared with the spinal-onset cases. These differences might be related to the higher age of the bulbar-onset patients. Further, no correlations were found between CSF tau concentrations and the rate of progression of the disease. CONCLUSIONS: These results do not support the hypothesis that total CSF tau protein is a reliable biological marker for ALS.

The importance of the reproducibility of oropharyngeal swallowing in amyotrophic lateral sclerosis. An electrophysiological study.

OBJECTIVE: To investigate electrophysiologically the reproducibility of oropharyngeal swallowing in patients with ALS. METHODS: We enrolled 26 ALS patients, both with and without clinical signs of dysphagia, and 30 age-matched controls. The reproducibility of the electrophysiological signals related to the oral phase (electromyographic activity of the submental/suprahyoid muscles) and the pharyngeal phase (laryngeal-pharyngeal mechanogram) of swallowing across repeated swallows was assessed. To do this we computed two similarity indexes (SI) by using previously described mathematical algorithms. RESULTS: The reproducibility of oropharyngeal swallowing was significantly reduced both in patients with and in those without clinical signs of dysphagia, with more marked alterations being detected in the dysphagic group. The SI of both phases of swallowing, oral and pharyngeal, correlated significantly with dysphagia severity and disease severity. CONCLUSIONS: In ALS different pathophysiological mechanisms can alter the stereotyped motor behaviors underlying normal swallowing, thus reducing the reproducibility of the swallowing act. A decrease in swallowing reproducibility could be a preclinical sign of dysphagia and, beyond a certain threshold, a pathological hallmark of oropharyngeal dysphagia. SIGNIFICANCE: Electrophysiological assessment is a simple and useful tool for the early detection of swallowing abnormalities, and for the management of overt dysphagia in ALS.

Multimodal Approach of Pulmonary Artery Intimal Sarcoma: A Single-Institution Experience.

INTRODUCTION: Pulmonary artery sarcoma (PAS) is a rare tumor, whose therapeutic approach is mainly based on surgery, either pneumonectomy or pulmonary endarterectomy (PEA). The prognosis reported in published series is very poor, with survival of 1.5 months without any kind of treatment. PATIENTS AND METHODS: From January 2010 to January 2016, 1027 patients were referred to our hospital for symptoms of acute or chronic pulmonary thromboembolic disease. Twelve patients having a confirmed diagnosis of PAS underwent PEA. Median age was 64.5 years. Most patients had a long history of symptoms, having a median time of 7.5 months from onset of symptoms to surgery. RESULTS: Following PEA and cardiopulmonary rehabilitation, 10 patients received conventional chemotherapy with doxorubicin and ifosfamide, starting at a median of 42 days from surgery. Four patients also received radiotherapy. Four patients have died due to disease progression, while 7 are still alive, with 5 being disease-free at 4-55+ months from diagnosis. CONCLUSIONS: In patients with PAS, a multimodal approach including PEA, CT, and RT is feasible but it should be evaluated individually, according to the tumor extension and the patient's clinical condition. Apart from improving quality of life mainly by reducing or delaying symptoms due to PH, it may improve life expectancy.

How cellular membrane properties are affected by the actin cytoskeleton.

Lipid membranes define the boundaries of living cells and intracellular compartments. The dynamic remodelling of these membranes by the cytoskeleton, a very dynamic structure made of active biopolymers, is crucial in many biological processes such as motility or division. In this review, we present some aspects of cellular membranes and how they are affected by the presence of the actin cytoskeleton. We show that, in parallel with the direct study of membranes and cytoskeleton in vivo, biomimetic in vitro systems allow reconstitution of biological processes in a controlled environment. In particular, we show that liposomes, or giant unilamellar vesicles, encapsulating a reconstituted actin network polymerizing at their membrane are suitable models of living cells and can be used to decipher the relative contributions of membrane and actin on the mechanical properties of the cellular interface.

Frontal Tendon Lengthening Plasty for Treatment of Structural Patella Baja.

Patella baja is a severe complication seen after trauma, prolonged immobilization and surgery. Several surgical methods have been described to proximalize the patella without a change in the patella tendon length. Yet, patella tendon shortening and thickening can be regarded as the hallmark pathology. As such, we describe a technique for the lengthening of the patellar tendon to pathoconformly address underlying patella baja. The technique is reproducible and gives the possibility of an early postoperative mobilization to prevent re-baja-a typical complication after patella baja surgery.

SPECT imaging of fluorine-18.

UNLABELLED: The objective of this work was to determine the potential clinical usefulness of SPECT to image 511-keV annihilation photons. METHODS: A triple-headed gamma camera equipped with ultra-high-energy collimators was used to image 18F. Sensitivity measurements were carried out and the FWHM and FWTM were determined in air and for a unit-density scattering medium. Additionally, tomographic phantom studies were acquired to evaluate image quality. RESULTS: The sensitivities of the three cameras were, for all practical purposes, identical. At a source-to-collimator distance of 100 mm, the FWHM and FWTM were 13 and 29 mm, respectively. A tomographic phantom study demonstrated that spheres with a diameter of 20 mm were well resolved when filled with 18F activity and placed inside a water-filled phantom. CONCLUSION: The triple-headed SPECT camera in this investigation is a practical means of acquiring tomographic 18F images. The reconstructed slices were of sufficient quality to be of value in some clinical studies.