Creating high-resolution 3D cranial implant geometry using deep learning techniques.

Creating a personalized implant for cranioplasty can be costly and aesthetically challenging, particularly for comminuted fractures that affect a wide area. Despite significant advances in deep learning techniques for 2D image completion, generating a 3D shape inpainting remains challenging due to the higher dimensionality and computational demands for 3D skull models. Here, we present a practical deep-learning approach to generate implant geometry from defective 3D skull models created from CT scans. Our proposed 3D reconstruction system comprises two neural networks that produce high-quality implant models suitable for clinical use while reducing training time. The first network repairs low-resolution defective models, while the second network enhances the volumetric resolution of the repaired model. We have tested our method in simulations and real-life surgical practices, producing implants that fit naturally and precisely match defect boundaries, particularly for skull defects above the Frankfort horizontal plane.

Total Syntheses, Absolute Configurations, and Cytotoxicity Evaluation of Ugonstilbenes A, B, and C from the Rhizomes of Helminthostachys zeylanica.

This study describes the first and efficient syntheses of the naturally occurring ugonstilbenes A, B, and C. The stilbene skeleton was prepared using the Horner-Wadsworth-Emmons reaction. On the basis of their specific rotations, the absolute configurations of ugonstilbenes A and C were both determined to be R, while the absolute configuration of ugonstilbene B was determined as 4aS,9aR. The synthesized compounds showed cytotoxic activities against selected human cancer cell lines.

Three-dimensional deep learning to automatically generate cranial implant geometry.

We present a 3D deep learning framework that can generate a complete cranial model using a defective one. The Boolean subtraction between these two models generates the geometry of the implant required for surgical reconstruction. There is little or no need for post-processing to eliminate noise in the implant model generated by the proposed approach. The framework can be used to meet the repair needs of cranial imperfections caused by trauma, congenital defects, plastic surgery, or tumor resection. Traditional implant design methods for skull reconstruction rely on the mirror operation. However, these approaches have great limitations when the defect crosses the plane of symmetry or the patient's skull is asymmetrical. The proposed deep learning framework is based on an enhanced three-dimensional autoencoder. Each training sample for the framework is a pair consisting of a cranial model converted from CT images and a corresponding model with simulated defects on it. Our approach can learn the spatial distribution of the upper part of normal cranial bones and use flawed cranial data to predict its complete geometry. Empirical research on simulated defects and actual clinical applications shows that our framework can meet most of the requirements of cranioplasty.

Calf Circumference as an Optimal Choice of Four Screening Tools for Sarcopenia Among Ethnic Chinese Older Adults in Assisted Living.

INTRODUCTION: Sarcopenia is highly prevalent among residents of assisted-living facilities. However, the optimal screening tools are not clear. Therefore, we compared the performance of four recommended screening tools for predicting sarcopenia. METHODS: The study recruited 177 people over 65 years of age in assisted-living facilities. Appendicular muscle mass index was measured using bioelectrical impedance analysis. Calf circumference (CC), handgrip, six-meters walking speed, and screening questionnaires including SARC-CalF, SARC-F and 5-item Mini Sarcopenia Risk Assessment (MSRA-5) were evaluated. The diagnosis criteria for sarcopenia were based on the Asian Working Group for Sarcopenia 2019 consensus. The area under the receiver operating characteristic curves (AUC) was used to contrast the diagnostic accuracy of screening tools. RESULTS: The prevalence of sarcopenia was 52.7% among men and 51.2% among women. After adjusting for age, sex, body mass index and SARC-CalF score, CC remained significantly associated with sarcopenia in logistic regression analysis. The prediction model for sarcopenia based on CC alone had the highest accuracy compared to SARC-CalF, MSRA-5 and SARC-F (AUC, 0.819 vs 0.734 vs 0.600 vs 0.576; sensitivity/specificity, 80.4%/71.8% vs 38.0%/80.0% vs 60.7%/54.2% vs 10.9%/91.8%). Differences in AUCs between the prediction models were statistically significant (CC vs. SARC-CalF, P = 0.0181; SARC-CalF vs. MSRA-5, P = 0.0042). Optimal cutoff values for predicting sarcopenia were CC <34 cm in men and <33 cm in women. CONCLUSION: To predict sarcopenia based on low CC alone is accurate, easy and inexpensive for use in assisted-living facility settings. Further validation studies in different populations are suggested.

High-flow nasal cannula ventilation therapy for obstructive sleep apnea in ischemic stroke patients requiring nasogastric tube feeding: a preliminary study.

Obstructive sleep apnea (OSA) is associated with increasing risk of recurrent stroke and mortality. Nasogastric tubes used by dysphagic stroke patients may interfere with nasal continuous positive airway pressure (CPAP) due to air leakage. This study was evaluated the effects and short-term tolerability of high-flow nasal cannula (HFNC) therapy for OSA in stroke patients with nasogastric intubation. The HFNC titration study was performed in post-acute ischemic stroke patients with nasogastric intubation and OSA. Then, participants were treated with HFNC therapy in the ward for one week. Eleven participants (eight males) who were all elderly with a median age of 72 (IQR 67-82) years and a body mass index of 23.5 (IQR 22.0-26.6) completed the titration study. The HFNC therapy at a flow rate up to 50~60 L/min significantly decreased the apnea-hypopnea index from 52.0 events/h (IQR 29.9-61.9) to 26.5 events/h (IQR 3.3-34.6) and the total arousal index from 34.6 (IQR 18.6-42.3) to 15.0 (IQR 10.3-25.4). The oxygen desaturation index was also significantly decreased from 53.0 events/h (IQR 37.0-72.8) to 16.2 events/h (IQR 0.8-20.1), accompanied by a significant improvement in the minimum SpO2 level. Finally, only three participants tolerated flow rates of 50~60 L/minute in one-week treatment period. Conclusively, HFNC therapy at therapeutic flow rate is effective at reducing the OSA severity in post-acute ischemic stroke patients with nasogastric intubation. Owing to the suboptimal acceptance, HFNC might be a temporary treatment option, and CPAP therapy is suggested after the nasogastric tube is removed.

Poststroke Depressive Symptoms Are Associated With Increased Oxidative Deoxyribonucleic Acid Damage.

Poststroke depression is independently associated with poor health outcomes, such as increased mortality, disability, anxiety, and lower quality of life. Identifying the potential biomarkers and detailed mechanisms of poststroke depression may improve the effectiveness of therapeutic intervention. In this cross-sectional study, the authors recruited patients with subacute ischemic stroke who were consecutively admitted for neurorehabilitation. Depression was assessed with the Patient Health Questionnaire-9 (PHQ-9), with a cutoff based on a summed-items score of 10. Polysomnography and laboratory tests for oxidative stress and inflammation were arranged. In total, 139 patients (97 men [69.8%] and 42 women [30.2%]; mean age: 63.2 years [±13.4]) with recent ischemic stroke were recruited and divided into two groups based on their depressive symptoms. Body mass index (BMI), the Barthel Index, percentage of antidepressant usage, and percentage of rapid eye movement (REM) sleep differed significantly between the two groups. The PHQ-9 score was significantly correlated with the levels of total antioxidant capacity, C-reactive protein, and urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG). Urinary 8-OHdG, a marker of oxidative stress to DNA, remained significantly and positively correlated with PHQ-9 scores after adjusting for BMI, sleep-onset latency, Barthel Index, mean oxyhemoglobin saturation, age, antidepressant usage, and percentage of REM sleep by using multivariate linear regression. Depressive symptoms were related to increased oxidative DNA damage in patients with subacute ischemic stroke. Urinary 8-OHdG may serve as a potential biomarker for poststroke depression. Further longitudinal studies are needed to elucidate the causal relationship between poststroke depression and elevated oxidative stress level.

Quantum dot imaging for embryonic stem cells.

BACKGROUND: Semiconductor quantum dots (QDs) hold increasing potential for cellular imaging both in vitro and in vivo. In this report, we aimed to evaluate in vivo multiplex imaging of mouse embryonic stem (ES) cells labeled with Qtracker delivered quantum dots (QDs). RESULTS: Murine embryonic stem (ES) cells were labeled with six different QDs using Qtracker. ES cell viability, proliferation, and differentiation were not adversely affected by QDs compared with non-labeled control cells (P = NS). Afterward, labeled ES cells were injected subcutaneously onto the backs of athymic nude mice. These labeled ES cells could be imaged with good contrast with one single excitation wavelength. With the same excitation wavelength, the signal intensity, defined as (total signal-background)/exposure time in millisecond was 11 +/- 2 for cells labeled with QD 525, 12 +/- 9 for QD 565, 176 +/- 81 for QD 605, 176 +/- 136 for QD 655, 167 +/- 104 for QD 705, and 1,713 +/- 482 for QD 800. Finally, we have shown that QD 800 offers greater fluorescent intensity than the other QDs tested. CONCLUSION: In summary, this is the first demonstration of in vivo multiplex imaging of mouse ES cells labeled QDs. Upon further improvements, QDs will have a greater potential for tracking stem cells within deep tissues. These results provide a promising tool for imaging stem cell therapy non-invasively in vivo.