Influence of the Choice of Lunar Gravity Model on Orbit Determination for Lunar Orbiters

We examine the influence of the lunar gravity model on the orbit determination (OD) of a lunar orbiter operating in a 100 km high, lunar polar orbit. Doppler and sequential range measurements by three Deep Space Network antennas and one Korea Deep Space Antenna were used. For measurement simulation and OD analysis, STK11 and ODTK6 were utilized. GLGM2, LP100K, LP150Q, GRAIL420A, and GRAIL660B were used for investigation of lunar gravity model selection effect. OD results were assessed by position and velocity uncertainties with error covariance and an external orbit comparison using simulated true orbit. The effect of the lunar gravity models on the long-term OD, degree and order level, measurement-acquisition condition, and lunar altitude was investigated. For efficiency verification, computational times for the five lunar gravity models were compared. Results showed that significant improvements to OD accuracy are observed by applying a GRAIL-based model; however, applying a full order and degree gravity modeling is not always the best strategy, owing to the computational burden. Consequently, we consider that OD using GRAIL660B with 70 × 70 degree and order is the most efficient strategy for mission preanalysis. This study provides useful guideline for KPLO OD analysis during nominal mission operation

Evolution of the Selenopotential Model and Its Effects on the Propagation Accuracy of Orbits around the Moon

The current work analyzes the effect of applying different selenopotential models to the propagation of a lunar orbiting spacecraft. A brief evolution history of the selenopotential model is first presented; then, four representative selenopotential models are selected for force modeling. Expected propagation errors are presented with respect to three different circular polar orbits around the Moon. As a result, an expected but rather significant number of orbit propagation errors are discovered. Compared to the solutions obtained using the GRAIL1500E model, the overall 3D propagation errors for a 4-day period could reach up to several tens of kilometers (50 km altitude case with the GLGM2 model) and up to several hundreds of meters (50, 100, and 200 km altitude cases even with the GRAIL660B model). For each different orbiter’s altitude, the appropriate ranges of the degree and order of the gravitational harmonic coefficients are also suggested to yield the best propagation performances with respect to the performance obtained with the full harmonic coefficients using the GRAIL1500E model. The results of the current work are expected to serve as practical guidelines for the field of system budget analysis, mission design, mission operations, and the analysis of scientific results

Observational Arc-Length Effect on Orbit Determination for KPLO

In this study, orbit determination (OD) simulation for the Korea Pathfinder Lunar Orbiter (KPLO) was accomplished for investigation of the observational arc-length effect using a sequential estimation algorithm. A lunar polar orbit located at 100 km altitude and 90° inclination was mainly considered for the KPLO mission operation phase. For measurement simulation and OD for KPLO, the Analytical Graphics Inc. Systems Tool Kit 11 and Orbit Determination Tool Kit 6 software were utilized. Three deep-space ground stations, including two deep space network (DSN) antennas and the Korea Deep Space Antenna, were configured for the OD simulation. To investigate the arc-length effect on OD, 60-hr, 48-hr, 24-hr, and 12-hr tracking data were prepared. Position uncertainty by error covariance and orbit overlap precision were used for OD performance evaluation. Additionally, orbit prediction (OP) accuracy was also assessed by the position difference between the estimated and true orbits. Finally, we concluded that the 48-hr-based OD strategy is suitable for effective flight dynamics operation of KPLO. This work suggests a useful guideline for the OD strategy of KPLO mission planning and operation during the nominal lunar orbits phase

Adrenalectomy for Metastatic Disease to the Adrenal Gland from Gastric Cancer: Report of a Case

Metastases to the adrenal glands are frequently found at autopsy. In practice, adrenal metastases have generally been accepted as evidence of blood-borne systemic disease. So, clinically curable adrenal metastases is a rare malady. The role for surgical resection in adrenal metastases has not been clearly defined. A 45-year-old man initially underwent total gastrectomy with D2 lymph node dissection for treating his advanced gastric cancer. A solitary adrenal metastases was resected 1 year later. The patient has survived for 3 years and no further evidence of disease was found on his last follow-up examination. We report here on this case to show that for selected cases, surgical resection of adrenal metastases is feasible and this procedure may extend survival for metastatic gastric cancer patients

DIRECT CAROTID WALL SHEAR STRESS IN ACUTE CORONARY SYNDROME PATIENTS DECREASED AFTER ONE MONTH MEDICAL MANAGEMENT

Fuente Fuente, Carlos;Montes Gil, Antonio;Periel Piquer, Montserra

Clinical efficacy of prophylactic intravenous immunoglobulin for elderly DLBCL patients with hypogammaglobulinemia in the COVID-19 pandemic era

BackgroundElderly patients diagnosed with diffuse large B-cell lymphoma (DLBCL) undergoing reduced intensity R-CHOP therapy are at a heightened risk of acquiring infections, notably coronavirus disease 2019 (COVID-19) infection. This study aimed to evaluate the efficacy of intravenous immunoglobulin (IVIG) as prophylaxis against COVID-19 in this vulnerable population.MethodsA total of 125 elderly patients with DLBCL undergoing reduced intensity R-CHOP therapy were analyzed in this prospective, multicenter study. Patients with hypogammaglobulinemia were categorized into IVIG and non-IVIG groups, while those with normal immunoglobulin levels constituted the observation group. The study evaluated COVID-19 infection rates, therapy response, and safety outcomes.ResultsAmong the enrolled patients (median age: 77 years), 89 patients (71.2%) presented with hypogammaglobulinemia at diagnosis, and 56 patients enrolled in the IVIG administration group. IVIG administration remarkably reduced COVID-19 infection rates compared to non-IVIG recipients (8.9% vs. 24.6%; p =0.040). Notably, patients over 80 years old were more susceptible to COVID-19. Patients on IVIG exhibited good tolerance with manageable adverse events. Among patients with hypogammaglobulinemia who received IVIG, 40.5% of patients developed additional immunoglobulin deficiencies during chemotherapy. One or more new hypogammaglobulinemia occurred during chemotherapy in 72% of patients with hypogammaglobulinemia who did not receive IVIG, and in 61.3% of patients who did not have hypogammaglobulinemia at diagnosis.ConclusionIVIG showed promise in reducing COVID-19 infections among elderly patients with DLBCL receiving reduced intensity R-CHOP therapy. This highlights IVIG’s potential as a prophylactic measure, necessitating further investigation to optimize dosing, administration schedules, and potential interactions with vaccination strategies

Thermal spin injection and accumulation in CoFe/MgO/n-type Ge contacts

Understanding the interplay between spin and heat is a fundamental and intriguing subject. Here we report thermal spin injection and accumulation in CoFe/MgO/n-type Ge contacts with an asymmetry of tunnel spin polarization. Using local heating of electrodes by laser beam or electrical current, the thermally-induced spin accumulation is observed for both polarities of the temperature gradient across the tunnel contact. We observe that the magnitude of thermally injected spin signal scales linearly with the power of local heating of electrodes, and its sign is reversed as we invert the temperature gradient. A large Hanle magnetothermopower (HMTP) of about 7.0% and the Seebeck spin tunneling coefficient of larger than 0.74 meV K-1 are obtained at room temperature.1

A case of hepatocellular carcinoma in the caudate lobe successfully treated by transcatheter arterial chemoembolization using drug-eluting beads

Hepatocellular carcinoma (HCC) in the caudate lobe remains one of the most intricate locations where various treatments tend to pose problems with regard to the optimal approach. Surgical resection has been regarded as the most effective treatment; however, isolated resection of the caudate lobe is strenuous and associated with a high rate of early recurrence. Percutaneous ablation might be technically difficult or impossible to perform due to the deep location of tumors and adjacent large vessels. Treatment with drug-eluting beads (DEB) can potentially enhance the therapeutic efficacy for patients with unresectable HCC by drawing on the slower, more consistent drug delivery process. We described a case of a 62-year-old man with HCC in the caudate lobe who was successfully treated by DEB

Methylenetetrahydrofolate reductase C677T polymorphism in patients with gastric and colorectal cancer in a Korean population

<p>Abstract</p> <p>Background</p> <p>This study was designed to investigate an association between the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and the risk of gastric and colorectal cancer in the Korean population.</p> <p>Methods</p> <p>We conducted a population-based large-scale case-control study involving 2,213 patients with newly diagnosed gastric cancer, 1,829 patients with newly diagnosed colorectal cancer, and 1,700 healthy controls. Genotyping was performed with peripheral blood DNA for MTHFR C677T polymorphisms. The statistical significance was estimated by logistic regression analysis.</p> <p>Results</p> <p>The MTHFR C677T frequencies of CC, CT, and TT genotypes were 35.2%, 47.5%, and 17.3% among stomach cancer, 34%, 50.5%, and 15.5% in colorectal cancer, and 31.8%, 50.7%, and 17.5% in the controls, respectively. The MTHFR 677TT genotype showed a weak opposite association with colorectal cancer compared to the homozygous CC genotype [adjusted age and sex odds ratio (OR) = 0.792, 95% confidence interval (CI) = 0.638-0.984, <it>P </it>= 0.035]. Subjects with the MTHFR 677CT showed a significantly reduced risk of gastric cancer compared whose with the 677CC genotype (age- and sex-adjusted OR = 0.810; 95% CI = 0.696-0.942, <it>P </it>= 0.006). We also observed no significant interactions between the MTHFR C677T polymorphism and smoking or drinking in the risk of gastric and colorectal cancer.</p> <p>Conclusions</p> <p>The T allele was found to provide a weak protective association with gastric cancer and colorectal cancer.</p