Rheology and Printability of a Porcelain Clay Paste for DIW 3D Printing of Ceramics with Complex Geometric Structures.

The modeling of ceramics with complex geometric structures currently depends on the handcrafted mode, with long cycles, high costs, and low efficiency; additive manufacturing (AM) technology can solve this problem well. Herein, the porcelain clay paste was successfully prepared for the direct ink writing (DIW) 3D printing process of ceramics with complex geometric structures, and the effects of sodium citrate (SC) content on the rheological properties and DIW 3D printability of the porcelain clay paste were investigated in detail. The SC has a vital role in the rheological behavior of porcelain clay paste. Adding SC increases the absolute zeta potential and decreases the viscosity of the paste, while a high SC content will lead to a low storage modulus of the paste. The porcelain clay paste with an SC content of 0.05% and a paste solid content of 75% possesses suitable rheological properties and a storage modulus for DIW 3D printing. The as-prepared porcelain clay paste has high DIW 3D printability at a pressure of 0.5 MPa, and a 3D-printed green body with a well-densified structure can be achieved. After being sintered, the 3D-printed ceramic exhibits high densification and mechanical properties. A green body with complex geometric structures is quickly and precisely modeled by the DIW 3D printing process with the resultant porcelain clay paste as the raw material. This work provides a practical approach to rapidly fabricating ceramics with complex geometrical structures.

Magnetic resonance imaging findings of a case with Wolffian tumor and related literature review.

Background: Wolffian tumors in females are rare gynecological neoplasms, with fewer than 100 cases reported. Existing literature primarily focuses on the pathology, and reports involving imaging are limited. Objective: This study presents a case of Wolffian tumor, emphasizing its magnetic resonance imaging (MRI) characteristics to enhance preoperative diagnostic accuracy. Case report: A 56-year-old woman presented with a year-long history of irregular vaginal bleeding. MRI revealed a solid mass in the right adnexal region. On T2-weighted images, the mass exhibited slightly elevated signal intensity with a distinctive low-signal intensity rim. Diffusion-weighted imaging displayed markedly increased signal intensity, and the contrast enhancement was moderate. The patient underwent laparoscopic right adnexectomy and received a Wolffian tumor diagnosis. No recurrence was observed during a 6-month follow-up. Conclusions: Wolffian tumors exhibit distinctive MRI presentations. Notably, the prominent low-signal intensity rim on MRI may aid in accurate preoperative tumor diagnosis.

Development and validation of a radiomics-based nomogram for the preoperative prediction of microsatellite instability in colorectal cancer.

BACKGROUND: Preoperative prediction of microsatellite instability (MSI) status in colorectal cancer (CRC) patients is of great significance for clinicians to perform further treatment strategies and prognostic evaluation. Our aims were to develop and validate a non-invasive, cost-effective reproducible and individualized clinic-radiomics nomogram method for preoperative MSI status prediction based on contrast-enhanced CT (CECT)images. METHODS: A total of 76 MSI CRC patients and 200 microsatellite stability (MSS) CRC patients with pathologically confirmed (194 in the training set and 82 in the validation set) were identified and enrolled in our retrospective study. We included six significant clinical risk factors and four qualitative imaging data extracted from CECT images to build the clinics model. We applied the intra-and inter-class correlation coefficient (ICC), minimal-redundancy-maximal-relevance (mRMR) and the least absolute shrinkage and selection operator (LASSO) for feature reduction and selection. The selected independent prediction clinical risk factors, qualitative imaging data and radiomics features were performed to develop a predictive nomogram model for MSI status on the basis of multivariable logistic regression by tenfold cross-validation. The area under the receiver operating characteristic (ROC) curve (AUC), calibration plots and Hosmer-Lemeshow test were performed to assess the nomogram model. Finally, decision curve analysis (DCA) was performed to determine the clinical utility of the nomogram model by quantifying the net benefits of threshold probabilities. RESULTS: Twelve top-ranked radiomics features, three clinical risk factors (location, WBC and histological grade) and CT-reported IFS were finally selected to construct the radiomics, clinics and combined clinic-radiomics nomogram model. The clinic-radiomics nomogram model with the highest AUC value of 0.87 (95% CI, 0.81-0.93) and 0.90 (95% CI, 0.83-0.96), as well as good calibration and clinical utility observed using the calibration plots and DCA in the training and validation sets respectively, was regarded as the candidate model for identification of MSI status in CRC patients. CONCLUSION: The proposed clinic-radiomics nomogram model with a combination of clinical risk factors, qualitative imaging data and radiomics features can potentially be effective in the individualized preoperative prediction of MSI status in CRC patients and may help performing further treatment strategies.

Computed tomography-based radiomic analysis for prediction of treatment response to salvage chemoradiotherapy for locoregional lymph node recurrence after curative esophagectomy.

OBJECTIVE: To investigate the capability of computed tomography (CT) radiomic features to predict the therapeutic response and local control of the locoregional recurrence lymph node (LN) after curative esophagectomy by chemoradiotherapy. METHODS: This retrospective study included 129 LN from 77 patients (training cohort: 102 LN from 59 patients; validation cohort: 27 LN from 18 patients) with postoperative esophageal squamous cell carcinoma (ESCC). The region of the tumor was contoured in pretreatment contrast-enhanced CT images. The least absolute shrinkage and selection operator with logistic regression was used to identify radiomic predictors in the training cohort. Model performance was evaluated using the area under the receiver operating characteristic curves (AUC). The Kaplan-Meier method was used to determine the local recurrence time of cancer. RESULTS: The radiomic model suggested seven features that could be used to predict treatment response. The AUCs in training and validated cohorts were 0.777 (95% CI: 0.667-0.878) and 0.765 (95% CI: 0.556-0.975), respectively. A significant difference in the radiomic scores (Rad-scores) between response and nonresponse was observed in the two cohorts (p < 0.001, 0.034, respectively). Two features were identified for classifying whether there will be relapse in 2 years. AUC was 0.857 (95% CI: 0.780-0.935) in the training cohort. The local control time of the high Rad-score group was higher than the low group in both cohorts (p < 0.001 and 0.025, respectively). As inferred from the Cox regression analysis, the low Rad-score was a high-risk factor for local recurrence within 2 years. CONCLUSIONS: The radiomic approach can be used as a potential imaging biomarker to predict treatment response and local control of recurrence LN in ESCC patients.

COVID-19 with acute cholecystitis: a case report.

BACKGROUND: The 2019 novel coronavirus (COVID-19) presents a major threat to public health and has rapidly spread worldwide since the outbreak in Wuhan, Hubei Province, China in 2019. To date, there have been few reports of the varying degrees of illness caused by the COVID-19. CASE PRESENTATION: A case of 68-year-old female with COVID-19 pneumonia who had constant pain in the right upper quadrant of her abdomen during her hospitalization that was finally diagnosed as acute cholecystitis. Ultrasound-guided percutaneous transhepatic gallbladder drainage (PTGD) was performed, and the real-time fluorescence polymerase chain reaction (RT-PCR) COVID-19 nucleic acid assay of the bile was found to be negative. PTGD, antibacterial and anti-virus combined with interferon inhalation treatment were successful. CONCLUSION: The time course of chest CT findings is typical for COVID-19 pneumonia. PTGD is useful for acute cholecystitis in COVID-19 patients. Acute cholecystitis is likely to be caused by COVID-19 .

CASH 2021: commercial access and space habitation.

Issues about commercialization of space have been a growing concern in the past decade for the space community. This paper focuses on the work from a team of 51 students attending the Summer Session Program of the International Space University in Bremen, Germany. CASH 2021 (Commercial Access and Space Habitation) documents a plan that identifies commercial opportunities for space utilization that will extend human presence in space, and will chart the way forward for the next 20 years. The group selected four commercial sectors that show the most promise for the future: tourism, entertainment, space system service, assembly and debris removal, and research and development/production. The content of this document presents the results of their research. Historical activities in each of the commercial sectors are reviewed along with the current market situation. To provide a coherent background for future commercialization possibilities a scenario has been developed. This scenario includes a postulated upon ideal future and includes social, political and economic factors that may affect the space industry over the timeline of the study. The study also presents a roadmap, within the limited optimistic scenario developed, for the successful commercialization of space leading to future human presence in space. A broad range of commercially viable opportunities, not only within the current limits of the International Space Station, but also among the many new developments that are expected by 2021 are discussed.