VV16: The First VEGA Rideshare Mission Flight

The SSMS (Small Spacecraft Mission Service) program is a new multi-launch concept for the Vega and Vega C launchers, thanks to a new modular dispenser for the Small Satellites Market. The Vega Proof of Concept (POC) flight using the SSMS hardware was developed in the context of ESA LLL Initiative (Light satellite, Low cost, launch opportunities) to provide solutions and services for the 1-400 kg mass class. The SSMS POC mission is foreseen to fly on VEGA VV16 flight on August 2020, following the last flight VV15 in July 2019. The paper describes the lesson learned of this first rideshare mission flight due to late definition or evolution of the satellites aggregate. On one hand the missionization process needs to become more standardized and with increased genericity (ad-hoc margin policy) in order to cover the continuous changes. On the other hand, the satellites should try to adapt to the standardized SSMS interfaces to simplify and shorten the mission preparation time. Based on the accumulated experience of the previous flights, the development of the multi-Payload mission concept started from the analysis of the activities to fly a single payload mission adapted to the needs of multi payload rideshare missions. Aggregation activities partially performed in Europe for the first time and completed in French Guiana, assembling, testing and integration into the Payload fairing, as well as relationships with clients and operators during the flight preparation campaign are not reported in this paper. Vega SSMS first Mission carried 43 different satellites ranging from 1 to 150 Kg from more than 10 different operators; this milestone represents a major advancement towards the goal to provide access to space for Small Satellite

The mechanism of iron binding processes in erionite fibres

Fibrous erionite-Na from Rome (Oregon, USA) was K-exchanged and characterized from the structural point of view. In addition, the modifications experienced after contact with a Fe(II) source were investigated for evaluating if the large potassium ions, blocking off nearly all the erionite cavity openings, might prevent the Fe(II) binding process, which is currently assumed to be one of the reasons of the toxicity of erionite. The K-exchanged sample had a 95% reduction of the BET surface area indicating that it behaves as a mesoporous material. Exchanged K is segregated at K2 and at OW sites commonly occupied by H2O. The latter K cations provide a relevant contribution to the reduction of the surface area. Surprisingly, despite the collapse of its surface area the sample preserves the tendency to bind Fe(II). Therefore, yet in the case of a peculiar and potentially hostile structural environment the Fe(II) ion-exchange process has essentially the same kinetics observed in a typical erionite sample. This is a clear evidence of the very limited effect of the chemical composition of erionite on the Fe(II) binding process and reasonably it does not play a significant role in its toxicity

VV16: The First VEGA Rideshare Mission: Lessons Learnt after Successful Flight

The SSMS (Small Spacecraft Mission Service) program is a new multi-launch concept for the Vega and Vega C launchers, thanks to a new modular dispenser for the Small Satellites Market. The Vega Proof of Concept (POC) flight using the SSMS hardware was developed to provide solutions and services for the 1-400 kg mass class. The SSMS POC mission has successfully flown on VEGA VV16 flight on September 3rd, 2020. The paper describes the lesson learned after this first rideshare mission flight. Vega SSMS first Mission carried 43 different satellites ranging from 1 to 150 Kg from more than 10 different operators. Several challenges had to be dealt with. The missionization process had to be standardized and with increased genericity (ad-hoc margin policy) to cover the continuous changes (of satellites or at least of locations in the dispensers). To simplify and shorten the mission preparation time, from customer side, the satellites designers have tried to adapt to the standardized SSMS interfaces. The trajectory profile is more complex than a standard VEGA single mission. Several main engine boosts are designed to release the satellites in a sequence of separations and collision avoidance maneuvers. The paper presents the outcomes of the successful flight and the information collected from the different measurements. The accelerometers located in the upper part show that the random and shock environment, as well as the low frequency environment, sensed at the levels of the different structures including the satellites, are compatible with the predictions and the specifications. The same good consistency between measurements, predictions and specifications has been found on the thermal properties sensed by the satellites. The separation of the satellites has been observed thanks to different measurements. The inertial navigation system (INS) outputs, which are standard in the telemetry, provide good observation of the separation sequences in terms of direction and norm of the impulses generated by the various separation devices. In addition, dedicated cameras were present to film the satellites immediately after the separation and to check their good respective disposals in terms of attitude and position. The orbital accuracy has also been verified as normal work (by using not only the Navigation information but also the GNSS outputs). It is very good thanks to Guidance algorithms and Navigation performances. In the last chapter of the paper, we also couple the lessons learnt after VV16 flight with the on-going missionization of VV18 (to be flown on April 2021) and VV19 (to be flown on June 2021). They are not strictly speaking full SSMS missions, but they share strong commonalities with VV16 in terms of dispensers for CubeSats separations

Is the double cross flap technique the panacea for avoiding fistula formation in hypospadias surgery?

Objective The aim of this study was to analyze retrospectively the 9-year experience of a single institution in the use of the double cross flap technique to interpose a double dartos flap to protect the neourethra with the aim of preventing fistula formation.Patients and methods Between October 2005 and September 2014 a total of 127 children with distal and midshaft primary hypospadias underwent tubularized incised plate urethroplasty by means of a double dartos flap obtained with a double cross flap to protect the neourethra. A Foley catheter was left in situ for 7 days. Success was defined as no incidence of complications requiring reintervention, along with good cosmetic result. A questionnaire was administered to estimate parental satisfaction. Parents were asked to evaluate the cosmetic appearance of the penis as good, acceptable, bad, or indifferent.Results The patient age at the time of surgery ranged from 12 months to 10 years (median 39 months). Three patients exhibited fistula at follow-up (2.3%). In two patients a glandular dehiscence of the urethroplasty occurred (1.5%). Mild stenosis of the neomeatus occurred in three patients (2.3%). No penile iatrogenic rotation occurred. A ‘good’ cosmetic result was reported by 68.5% of parents, acceptable by 22.8%, bad by 3.9% and indifferent by 4.7% of parents as per the parental questionnaire.Conclusion The double cross flap technique is not the panacea to prevent fistula formation in hypospadias surgery. Nevertheless, it offers an unquestionable advantage in terms of avoidance of fistula formation. The experience and skills of the surgeon performing urethroplasty remain the mainstay for best results

Mesenteric cystic lymphangioma mimicking an ileo-colic intussusception

Lymphangioma accounts for 5% of benign pediatric tumors and less than 1% is located in the abdomen. Indeed mesenteric cystic lymphangioma is a rare benign abdominal mass and its pathogenesis is still unknown.Mesenteric cystic lymphangioma is often diagnosed incidentally. Nevertheless, in some cases its clinical presentation can mimic several common surgical pathologies. Here we describe a case of mesenteric cystic lymphangioma mimicking an ileo-colic intussusception

Different Erionite Species Bind Iron into the Structure: A Potential Explanation for Fibrous Erionite Toxicity

In this investigation, the crystal chemical characterization of one sample of woolly erionite-K (Lander County, NV, USA) was examined after suspension in a FeCl2 solution, in anaerobic conditions. The aim of this study was to determine the effect of the chemical composition of erionite on its efficiency to bind iron. Inductively coupled plasma (ICP) results showed that the sample bound Fe(II) through an ion-exchange mechanism mainly involving Ca. In addition, chemical and structural data indicated that Fe(II) is fixed at the Ca3 site, six-fold coordinated to water molecules. According to Brunauer–Emmett–Teller (BET) sample surface area the amount of Fe(II) bound by the fibers was comparable with that retrieved for fibrous erionite-Na sample from Rome (OR, USA) for which the ion-exchange process mainly affected Na. This finding provides clear evidence of a strong tendency of Fe(II) to bind to the erionite structure. Furthermore, considering that the woolly erionite-K from Langer County differs markedly from erionite-Na from Rome in the extra-framework cation content, our observations indicate that the Fe binding efficiency is not significantly modulated by the chemical composition. Notably, Fe ion-exchanged and/or accumulated on the fiber surface can generate hydroxyl radicals via the Fenton reaction, thus influencing the potential carcinogenicity of the different erionite species

Loss of GATA-1 full length as a cause of Diamond-Blackfan anemia phenotype

Mutations in the hematopoietic transcription factor GATA-1 alter the proliferation/differentiation of hemopoietic progenitors. Mutations in exon 2 interfere with the synthesis of the full-length isoform of GATA-1 and lead to the production of a shortened isoform, GATA-1s. These mutations have been found in patients with Diamond-Blackfan anemia (DBA), a congenital erythroid aplasia typically caused by mutations in genes encoding ribosomal proteins. We sequenced GATA-1 in 23 patients that were negative for mutations in the most frequently mutated DBA genes. One patient showed a c.2T > C mutation in the initiation codon leading to the loss of the full-length GATA-1 isoform

Content, mineral allocation and leaching behavior of heavy metals in urban PM2.5

This work provides a novel perspective in the field of urban airborne particle investigation that is not currently found in the literature. Four sampling campaigns were performed in the urban area of Rome (Central Italy) during the winter and summer seasons (February and July 2013 and 2014, respectively). The measured concentrations of the regulated 34 elements of As, Cd, Ni and Pb were consistent with those reported by the local Environmental Agency (ARPA Lazio), but non-regulated heavy metals, including Fe, Cu, Cr and Zn, were also found in PM2.5 and analyzed in detail. As an novelty, heavy metals were associated with the host-identified mineral phases, primarily oxides and alloys, and to a lesser extent, other minerals, such as sulfates, carbonates and silicates. Leaching tests of the collected samples were conducted in a buffered solution mimicking the bodily physiological environment. Despite the highest concentration of heavy metals found during the winter sampling period, all of the elements showed a leaching trend leading to major mobility during the summer period. To explain this result, an interesting comparative analysis between the leaching test behavior and innovative mineral allocation was conducted. Both the heavy metal content and mineral allocation in PM2.5 might contribute to the bioavailability of toxic elements in the pulmonary environment. Hence, for regulatory purposes, the non-linear dependency of heavy metal bioavailability on the total metal content should be taken into account

Modelling the Fenton reaction of amphibole asbestos

In this work a sample of UICC crocidolite and a sample of fibrous tremolite were leached up to 1 week both in a simplified Gamble’s solution at acidic pH and in a phosphate buffered medium at neutral pH, in presence of H2O2. Surface chemical modifications were monitored by XPS spectroscopy. Subsequently, the generation of HO• radicals following reaction of both pristine and leached fibres with H2O2 (Fenton reaction) was investigated by spin trapping/EPR spectroscopy, with the aim of better clarifying the relationships between possible surface alteration occurring in vivo and chemical reactivity of amphibole asbestos. Moreover, the generation of HO• radicals was monitored on thermally treated fibres after leaching in phosphate buffered medium at neutral pH and in presence of H2O2 to investigate how chemical reactivity may be modulated by Fe oxidation state. Results showed that, for both amphibole asbestos, the surface alteration following incubation in the modified Gamble’s solution does not alter HO• radical generation. Interestingly, leaching in phosphate buffered solution in presence of H2O2 induced a progressive increase in HO• release for crocidolite fibres, whereas a strong reduction was observed for asbestos tremolite. This behaviour is likely due to the quicker alteration of the crocidolite surface due to the interaction with H2O2, as indicated by XPS analysis. In particular, the oxidation induced by H2O2 promotes the dissolution of the first atomic layer of the crocidolite structure and the following occurrence on its surface of new reactive Fe centres, particularly under the form of Fe(II), of which the bulk is richer than the oxidized surface. Accordingly, the heated samples showed a reduced, but not suppressed by thermal oxidation, chemical reactivity, with no significant evolution following incubation in phosphate buffered medium at neutral pH and in presence of H2O2