Development of an integrated heat pipe-thermal storage system for a solar receiver

The Organic Rankine Cycle (ORC) Solar Dynamic Power System (SDPS) is one of the candidates for Space Station prime power application. In the low Earth orbit of the Space Station approximately 34 minutes of the 94-minute orbital period is spent in eclipse with no solar energy input to the power system. For this period the SDPS will use thermal energy storage (TES) material to provide a constant power output. An integrated heat-pipe thermal storage receiver system is being developed as part of the ORC-SDPS solar receiver. This system incorporates potassium heat pipe elements to absorb and transfer the solar energy within the receiver cavity. The heat pipes contain the TES canisters within the potassium vapor space with the toluene heater tube used as the condenser region of the heat pipe. During the insolation period of the Earth orbit, solar energy is delivered to the heat pipe in the ORC-SDPS receiver cavity. The heat pipe transforms the non-uniform solar flux incident in the heat pipe surface within the receiver cavity to an essentially uniform flux at the potassium vapor condensation interface in the heat pipe. During solar insolation, part of the thermal energy is delivered to the heater tube and the balance is stored in the TES units. During the eclipse period of the orbit, the balance stored in the TES units is transferred by the potassium vapor to the toluene heater tube

Meso-scale turbulence in living fluids

Turbulence is ubiquitous, from oceanic currents to small-scale biological and quantum systems. Self-sustained turbulent motion in microbial suspensions presents an intriguing example of collective dynamical behavior amongst the simplest forms of life, and is important for fluid mixing and molecular transport on the microscale. The mathematical characterization of turbulence phenomena in active non-equilibrium fluids proves even more difficult than for conventional liquids or gases. It is not known which features of turbulent phases in living matter are universal or system-specific, or which generalizations of the Navier-Stokes equations are able to describe them adequately. Here, we combine experiments, particle simulations, and continuum theory to identify the statistical properties of self-sustained meso-scale turbulence in active systems. To study how dimensionality and boundary conditions affect collective bacterial dynamics, we measured energy spectra and structure functions in dense Bacillus subtilis suspensions in quasi-2D and 3D geometries. Our experimental results for the bacterial flow statistics agree well with predictions from a minimal model for self-propelled rods, suggesting that at high concentrations the collective motion of the bacteria is dominated by short-range interactions. To provide a basis for future theoretical studies, we propose a minimal continuum model for incompressible bacterial flow. A detailed numerical analysis of the 2D case shows that this theory can reproduce many of the experimentally observed features of self-sustained active turbulence.Comment: accepted PNAS version, 6 pages, click doi for Supplementary Informatio

Racial disparity in cardiac procedures and mortality among long-term survivors of cardiac arrest

Background— It is unknown whether white and black Medicare beneficiaries have different rates of cardiac procedure utilization or long-term survival after cardiac arrest. Methods and Results— A total of 5948 elderly Medicare beneficiaries (5429 white and 519 black) were identified who survived to hospital discharge between 1990 and 1999 after admission for cardiac arrest. Demographic, socioeconomic, and clinical information about these patients was obtained from Medicare administrative files, the US census, and the American Hospital Association’s annual institutional survey. A Cox proportional hazard model that included demographic and clinical predictors indicated a hazard ratio for mortality of 1.30 (95% CI 1.09 to 1.55) for blacks aged 66 to 74 years compared with whites of the same age. The addition of cardiac procedures to this model lowered the hazard ratio for blacks to 1.23 (95% CI 1.03 to 1.46). In analyses stratified by race, implantable cardioverter-defibrillators (ICDs) had a mortality hazard ratio of 0.53 (95% CI 0.45 to 0.62) for white patients and 0.50 (95% CI 0.27 to 0.91) for black patients. Logistic regression models that compared procedure rates between races indicated odds ratios for blacks aged 66 to 74 years of 0.58 (95% CI 0.36 to 0.94) to receive an ICD and 0.50 (95% CI 0.34 to 0.75) to receive either revascularization or an ICD. Conclusions— There is racial disparity in long-term mortality among elderly cardiac arrest survivors. Both black and white patients benefited from ICD implantation, but blacks were less likely to undergo this potentially life-saving procedure. Lower rates of cardiac procedures may explain in part the lower survival rates among black patients

The MLL-Menin Interaction is a Therapeutic Vulnerability in <em>NUP98</em>-rearranged AML

\ua9 2023 Wolters Kluwer Health. All rights reserved. Chromosomal translocations involving the NUP98 locus are among the most prevalent rearrangements in pediatric acute myeloid leukemia (AML). AML with NUP98 fusions is characterized by high expression of HOXA and MEIS1 genes and is associated with poor clinical outcome. NUP98 fusion proteins are recruited to their target genes by the mixed lineage leukemia (MLL) complex, which involves a direct interaction between MLL and Menin. Here, we show that therapeutic targeting of the Menin-MLL interaction inhibits the propagation of NUP98-rearrranged AML both ex vivo and in vivo. Treatment of primary AML cells with the Menin inhibitor revumenib (SNDX-5613) impairs proliferation and clonogenicity ex vivo in long-term coculture and drives myeloid differentiation. These phenotypic effects are associated with global gene expression changes in primary AML samples that involve the downregulation of many critical NUP98 fusion protein-target genes, such as MEIS1 and CDK6. In addition, Menin inhibition reduces the expression of both wild-type FLT3 and mutated FLT3-ITD, and in combination with FLT3 inhibitor, suppresses patient-derived NUP98-r AML cells in a synergistic manner. Revumenib treatment blocks leukemic engraftment and prevents leukemia-associated death of immunodeficient mice transplanted with NUP98::NSD1 FLT3-ITD-positive patient-derived AML cells. These results demonstrate that NUP98-rearranged AMLs are highly susceptible to inhibition of the MLL-Menin interaction and suggest the inclusion of AML patients harboring NUP98 fusions into the clinical evaluation of Menin inhibitors

Systems biological and mechanistic modelling of radiation-induced cancer

This paper summarises the five presentations at the First International Workshop on Systems Radiation Biology that were concerned with mechanistic models for carcinogenesis. The mathematical description of various hypotheses about the carcinogenic process, and its comparison with available data is an example of systems biology. It promises better understanding of effects at the whole body level based on properties of cells and signalling mechanisms between them. Of these five presentations, three dealt with multistage carcinogenesis within the framework of stochastic multistage clonal expansion models, another presented a deterministic multistage model incorporating chromosomal aberrations and neoplastic transformation, and the last presented a model of DNA double-strand break repair pathways for second breast cancers following radiation therapy

Disruption of a Yeast ADE6 Gene Homolog in Ustilago maydis

A putative homolog of the Sacharromyces cereviseae ADE6 and Escherichia coli purL genes is identified near a multigenic complex, which contains two genes, sid1 and sid2, involved in a siderophore biosynthetic pathway inUstilago maydis. The putative ADE6 homolog was mutated by targeted gene disruption. The resulting mutant strains demonstrated a requirement for exogenous adenine, indicating that the U. maydis ade6 homolog is required for purine biosynthesis

Clinical impact of MDR1-expression in testicular germ cell cancer

Aim: The multidrug resistance protein 1 (MDR1, P-gp, p-170) is a membrane glycoprotein that acts as an energy-dependent drug efflux pump. In various malignancies its expression is associated with resistance to diverse cytostatic drugs, and therefore predicts resistance to systemic treatment. The aim of this study was to investigate the prognostic value of MDR1 expression in primary tumor tissue to predict necrosis or viable cancer in residual tumor masses after systemic chemotherapy for advanced testicular germ cell cancer. Materials and Methods: Out of 77 patients, histopathological characteristics of primary testicular cancer specimens and retroperitoneal lymph node dissection (RPLND) samples following chemotherapy were available from 72 and all 77 patients, respectively. Moreover, MDR1 expression was determined by immunohistochemistry in 47 primary tumors and corresponding 73 RPLND sections. Results: After chemotherapy and subsequent RPLND, the examination of residual tumor masses revealed that mature teratoma and active viable tumor were predominantly found in patients with non-seminoma (NSGCT; p = 0.048), especially in those with containing mature teratoma (p = 0.001). Moreover, using univariate analysis the expression of MDR1 in the primary testicular tumor predicted viable tumor/teratoma residues in RPLND sections (p = 0.003). However, in multivariate analysis including the tumors’ histological subtype, MDR1 expression alone failed to reach statistical significance as an independent prognostic marker for residual vital tumor (p ≥ 0.16). Conclusions: With the limited number of patients given, the correlation between MDR1 expression in primary testis cancer and active residual retroperitoneal disease after chemotherapy failed to reach statistical significance as in independent marker. Therefore, up to now routine MDR1 staining of testicular germ cell cancer samples should not be performed in clinical practice. However, as there was a clear trend, a larger number of patients suffering from metastatic non-seminomas should be studied, as MDR1 expression might have significant prognostic value in this particular subgroup of patients.Белок 1 множественной лекарств енной устойчив ости (MDR1, P-gp, p-170) – это мембранный гликопротеин, функционирующий как энергозависимый насос. При разл ичных фо рмах опухолей его экспр е ссия связана с устойчив о стью опухоли к различным цитостатикам, что может быть использовано для выбора типа терапии. Цель работы — исследование прогности- ческой значимости экспрессии MDR1 в ткани пе рвичной опухоли для оценки возмо жности раз вития некроза или сохран е ния живых клеток в остаточной ткани опухоли после применения системной химиотерапии на поздних стадиях герминативных опухолей яичка. Материалы и методы: про анализиро ваны гисто патоло гические характ е ристики пе рвично й те стикулярной опухоли и образцов, полученных при иссечении ретроперитонеальных лимфатических узлов (RPLND) после хими отерапии 72 и 77 бол ьных соотве тственно. Экспр ессию MDR1 определяли иммун огист охимич еским методом в 47 образцах первичн ой опухоли и соответствующих 73 ср RPLND. Результаты: после хими отерапии и последующей RPLNDисследовани е оста- точных опухолевых тканей показало, чтозрелая тератома и жизнеспособные опух олевые клетки выяв ляют преимущественно у больных, у которых не была обнаружена семинома (NSGCT; p = 0,048), особенно у так овых , у которых была тератома (p = 0,001). Более того, д анные одно факторного анализа показали, что экспр е ссия MDR1 в ткани пе рвично й те стику лярной опу- холи может служить прогностич еским факт ором сохран ения живых опух олевых клеток срезах RPLND (p = 0,003). О нак о применение мультифакторного анализа, в том числе с учетом гистологического подтипа опухоли, показало, что экспр е ссия MDR1 не имеет самостоятельной прогностической значимости для выявления живых остаточных опух олевых клеток (p 0,16). Выводы: ввиду небольшо йвыборкибольных не выяв лено статистически значимойкорреляции между экспр ессией MDR1 в первичной опухоли яичка и наличием активных резидуальных очагов поражения в ретроперитонеальном пространстве. В т о же время, учитывая выявленную тенденцию, экспрессию MDR1, в качестве возможного прогностич еского марк ера, имеет смысл исследовать именно у больных с метастатическими опухолями, не являющимися семиномой