Seismic reflections from the crystalline crust below the Continental Deep Drilling Site KTB-modeling and inference on reflector properties

The three-dimensional (3-D) reflection-seismic data set ISO-89 3D was recorded near the deep borehole KTB in southeastern Germany. Reflections from the SE1 reflector and from the top of the Erbendorf body (EB) in the upper crystalline crust can be identified in 5–10% of the single-shot sections. The reflectors have been first identified in previous studies of stacked and migrated seismic data. In this paper the velocity and density variations of these two structures are estimated in a new way using true amplitude single-shot (vibroseis) data. The method uses the direct wave Pg as a reference phase and models the amplitude ratios of the SE1 and EB reflections to Pg. Modeling in this paper uses a combination of ray theory and the reflectivity method, and the SE1 and the top of the EB are assumed to be obliquely oriented 1-D structures. Pg modeling shows that a depth-dependent velocity function within the uppermost crystalline basement explains the amplitudes and travel times of this phase with sufficient accuracy. The largest observed amplitude ratios SE1/Pg and EB/Pg are explained by laminated models with strong velocity contrasts and with reflection coefficients of magnitude 0.1–0.2 (SE1) and 0.05–0.15 (EB). The total thickness of the reflecting zones is less than ∼300 m. Pg amplitude modeling requires low Qp factors (<100) to a depth of ∼1 km, whereas at larger depths, values of several hundred are necessary to keep the SE1 and EB velocity contrasts in realistic ranges. Both reflectors can be interpreted as cataclastic zones. For the SE1 this interpretation agrees with the view that it is a steeply dipping thrust fault which continues the tectonic Franconian Lineament into the upper crust. We assume that the EB is the fractured top of a high-velocity zone at depths below ∼10 km, known from earlier wide-angle measurements. Both reflectors have large weakly reflecting or nonreflecting parts. The SE1 is nonreflecting at the intersection with the KTB borehole

Seismic studies around the Kola Superdeep Borehole, Russia

The Kola Superdeep Borehole (SG-3) provided an ideal opportunity to test hypotheses on the origins of crustal reflections and on the presence and seismic expression of fluids in the upper crust. The alternative sources of crustal reflections include compositional changes, shear zones, fluids, and metamorphic facies changes, all of which are represented at the well. Both the 38-km-long CDP section and the borehole VSPs in the range 2.2–6.0 km demonstrate the presence of reflections from dipping compositional layering, shear zones, and fluid-filled zones. Subhorizontal reflectivity zones are interpreted as horizontal fluid-filled fracture-type reservoir rocks. Results suggest the presence of fluids down to a depth of at least 12 km in the upper crust; the presence of these fluids lowering seismic velocity causes estimates of upper crustal composition to be too felsic

Организация рабочих процессов по рекрутингу доноров и заготовке реконвалесцентной плазмы в период пандемии COVID-19

Background. The pandemic of the new coronavirus infection has challenged the medical community for quickly finding and implementing effective methods of treatment. In the absence of a vaccine or specific therapy with proven effectiveness, the usage of convalescent plasma can be the one of perspective methods. An important aspect of this technology is the efficient and safe preparation of convalescent plasma. To date, in the world literature there are practically no publications about donor recruitment and the specifics of the preparation of convalescent plasma. Purpose of the research. Presentation of the experience of organizing a workflow for recruiting donors and stockpiling of convalescent plasma with a high titer of virus-neutralizing antibodies to SARS-CoV-2. Methods. The analysis of the work of the Blood Service of the Moscow Department of Health for stockpiling of COVID-19 convalescent plasma has been executed. In total it has been stockpiled 1240 doses. The normative documentation has been developed by a working group on the basis of the current federal legislation of Russian federation and been approved by the Moscow Department of Health. The titer of neutralizing antibodies (VNA) has been determined as the basic method for assessing the immunological viability of convalescent plasma. The main characteristics of donors, the characteristics of the disease course, the results of preliminary testing for the presence of specific antibodies by ELISA and CLIA methods has been compared with VNA titers in the stockpiled convalescent plasma. Results. Due to a Moscow Health Departments order No. 325 dated 01.04.2020 (a basic local regulatory document) it has been developed a regulation for the stockpiling, examination, storage, safety and transfering of fresh frozen pathogen-reduced plasma of COVID-19 convalescent donors to medical organizations of the Moscow Health Department. For arranging an interaction with donors it has been created a call-center. For effective preliminary selection, it has been formed a donor characteristics list, which has been combined with screening of specific antibodies by ELISA and CLIA methods. Conclusions. Developed a system of recruiting donors and procurement process of convalescent plasma for treatment СOVID-19, which includes the necessary regulations, algorithms for the selection and recruitment of donors, the registry of donors and recipients, algorithms, efficiency and safety of convalescent plasma.Обоснование. Пандемия новой коронавирусной инфекции поставила перед медицинским сообществом задачу быстрого поиска и внедрения эффективных методик лечения. В условиях отсутствия вакцины и средств специфической терапии с доказанной эффективностью в качестве одной из перспективных методик рассматривается трансфузия реконвалесцентной плазмы (РП). Важным аспектом данной технологии является заготовка эффективного и безопасного компонента. На сегодняшний день публикации по рекрутингу доноров и особенностях заготовки РП в мировой литературе практически отсутствуют. Цель исследования Анализ опыта организации рабочего процесса по привлечению доноров и заготовке РП с высоким титром вируснейтрализующих антител к SARS-CoV-2. Методы. Проведен анализ работы Службы крови Департамента здравоохранения г. Москвы (ДЗМ) по заготовке РП COVID-19. Всего заготовлено 1240 доз. Нормативная документация разработана рабочей группой на основании действующего федерального законодательства и утверждена ДЗМ. Как базовая методика оценки иммунологической состоятельности РП, определен титр вируснейтрализующих антител (ВНА). Проведено сопоставление основных характеристик доноров, особенностей течения заболевания, результатов предварительного тестирования на наличие специфических антител методами ИФА и ИХЛА с титрами ВНА заготовленной РП. Результаты. Работа по заготовке, обследованию, хранению, обеспечению безопасности и передаче в медицинские организации ДМЗ свежезамороженной патогенредуцированной плазмы доноров-реконвалесцентов COVID-19 была организована на основании приказа ДЗМ от 01.04.2020 № 325 как базового локального нормативного документа. Для оптимальной коммуникации с состоявшимися донорами и привлечения реконвалесцентов использовались ресурсы колл-центра. Для эффективного предварительного отбора доноров применялись анализ характеристик донора (плазма с наибольшими значениями титра ВНА ожидаема от доноров-мужчин, переболевших с признаками явной вирусной пневмонии) и результаты скрининга специфических антител методами ИФА и ИХЛА. Заключение. Разработана система обеспечения рекрутинга доноров и процесса заготовки РП для лечения СOVID-19, включающая необходимые нормативные документы, алгоритмы отбора и привлечения доноров, реестр доноров и реципиентов, алгоритмы обеспечения эффективности и безопасности РП

Impact of pathogen reduction methods on immunological properties of the COVID-19 convalescent plasma

Background and objectives: COVID-19 convalescent plasma is an experimental treatment against SARS-CoV-2. The aim of this study is to assess the impact of different pathogen reduction methods on the levels and virus neutralizing activity of the specific antibodies against SARS-CoV2 in convalescent plasma. Materials and methods: A total of 140 plasma doses collected by plasmapheresis from COVID-19 convalescent donors were subjected to pathogen reduction by three methods: methylene blue (M)/visible light, riboflavin (R)/UVB and amotosalen (A)/UVA. To conduct a paired comparison, individual plasma doses were divided into 2 samples that were subjected to one of these methods. The titres of SARS-CoV2 neutralizing antibodies (NtAbs) and levels of specific immunoglobulins to RBD, S- and N-proteins of SARS-CoV-2 were measured before and after pathogen reduction. Results: The methods reduced NtAbs titres differently: among units with the initial titre 80 or above, 81% of units remained unchanged and 19% decreased by one step after methylene blue; 60% were unchanged and 40% decreased by one step after amotosalen; after riboflavin 43% were unchanged and 50% (7%, respectively) had a one-step (two-step, respectively) decrease. Paired two-sample comparisons (M vs. A, M vs. R and A vs. R) revealed that the largest statistically significant decrease in quantity and activity of the specific antibodies resulted from the riboflavin treatment. Conclusion: Pathogen reduction with methylene blue or with amotosalen provides the greater likelihood of preserving the immunological properties of the COVID-19 convalescent plasma compared to riboflavin