Augmented Reality Navigation System for Biliary Interventional Procedures With Dynamic Respiratory Motion Correction

OBJECTIVE

Biliary interventional procedures require physicians to track the interventional instrument tip (Tip) precisely with X-ray image. However, Tip positioning relies heavily on the physicians' experience due to the limitations of X-ray imaging and the respiratory interference, which leads to biliary damage, prolonged operation time, and increased X-ray radiation.

METHODS

We construct an augmented reality (AR) navigation system for biliary interventional procedures. It includes system calibration, respiratory motion correction and fusion navigation. Firstly, the magnetic and 3D computed tomography (CT) coordinates are aligned through system calibration. Secondly, a respiratory motion correction method based on manifold regularization is proposed to correct the misalignment of the two coordinates caused by respiratory motion. Thirdly, the virtual biliary, liver and Tip from CT are overlapped to the corresponding position of the patient for dynamic virtual-real fusion.

RESULTS

Our system is respectively evaluated and achieved an average alignment error of 0.75 ± 0.17 mm and 2.79 ± 0.46 mm on phantoms and patients. The navigation experiments conducted on phantoms achieve an average Tip positioning error of 0.98 ± 0.15 mm and an average fusion error of 1.67 ± 0.34 mm after correction.

CONCLUSION

Our system can automatically register the Tip to the corresponding location in CT, and dynamically overlap the 3D virtual model onto patients to provide accurate and intuitive AR navigation.

SIGNIFICANCE

This study demonstrates the clinical potential of our system by assisting physicians during biliary interventional procedures. Our system enables dynamic visualization of virtual model on patients, reducing the reliance on contrast agents and X-ray usage.

PEA-Net: A progressive edge information aggregation network for vessel segmentation

Automatic vessel segmentation is a critical area of research in medical image analysis, as it can greatly assist doctors in accurately and efficiently diagnosing vascular diseases. However, accurately extracting the complete vessel structure from images remains a challenge due to issues such as uneven contrast and background noise. Existing methods primarily focus on segmenting individual pixels and often fail to consider vessel features and morphology. As a result, these methods often produce fragmented results and misidentify vessel-like background noise, leading to missing and outlier points in the overall segmentation. To address these issues, this paper proposes a novel approach called the progressive edge information aggregation network for vessel segmentation (PEA-Net). The proposed method consists of several key components. First, a dual-stream receptive field encoder (DRE) is introduced to preserve fine structural features and mitigate false positive predictions caused by background noise. This is achieved by combining vessel morphological features obtained from different receptive field sizes. Second, a progressive complementary fusion (PCF) module is designed to enhance fine vessel detection and improve connectivity. This module complements the decoding path by combining features from previous iterations and the DRE, incorporating nonsalient information. Additionally, segmentation-edge decoupling enhancement (SDE) modules are employed as decoders to integrate upsampling features with nonsalient information provided by the PCF. This integration enhances both edge and segmentation information. The features in the skip connection and decoding path are iteratively updated to progressively aggregate fine structure information, thereby optimizing segmentation results and reducing topological disconnections. Experimental results on multiple datasets demonstrate that the proposed PEA-Net model and strategy achieve optimal performance in both pixel-level and topology-level metrics.

CT radiomics can predict disease progression within 6 months after chimeric antigen receptor-modified T-cell therapy in relapsed/refractory B-cell non-Hodgkin's lymphoma patients

AIM

To predict progression within 6 months after chimeric antigen receptor-modified (CAR) T-cell therapy for relapsed/refractory (R/R) B-cell non-Hodgkin's lymphoma (B-NHL) patients by radiomic indexes derived from contrast-enhanced computed tomography (CECT) examinations.

MATERIALS AND METHODS

Seventy R/R B-NHL patients who underwent CECT before treatment with CAR T-cells were examined retrospectively. In total, 297 volumes of interest for lesions were segmented from CECT images. Patients without and with disease progression were assigned to groups 1 and 2, respectively. Radiomic and combined predictive models were constructed by three machine-learning algorithms using features from the training set, respectively. Furthermore, predictive models were constructed based on multi-lesion-based and largest-lesion-based radiomic features, respectively.

RESULTS

In the test set, no marked differences were observed between the areas under the curves (AUCs) of the combined and radiomic models for all three machine-learning algorithms (all p>0.05). Differences in machine-learning algorithms did not significantly affect the predictive performances of the models. Radiomics and combined models constructed with multi-lesion-based radiomic features showed better predictive performances than those applying largest-lesion-based radiomic features (all p<0.05 for comparisons between combined models).

CONCLUSION

CECT-based radiomic features may be applied to predict disease progression in R/R B-NHL patients within 6 months after CAR T-cell treatment, and radiomic features from multiple lesions may have better predictive efficacy. Different machine-learning algorithms may not show significant differences in prediction performance.

CT2X-IRA: CT to x-ray image registration agent using domain-cross multi-scale-stride deep reinforcement learning

Objective.In computer-assisted minimally invasive surgery, the intraoperative x-ray image is enhanced by overlapping it with a preoperative CT volume to improve visualization of vital anatomical structures. Therefore, accurate and robust 3D/2D registration of CT volume and x-ray image is highly desired in clinical practices. However, previous registration methods were prone to initial misalignments and struggled with local minima, leading to issues of low accuracy and vulnerability.Approach.To improve registration performance, we propose a novel CT/x-ray image registration agent (CT2X-IRA) within a task-driven deep reinforcement learning framework, which contains three key strategies: (1) a multi-scale-stride learning mechanism provides multi-scale feature representation and flexible action step size, establishing fast and globally optimal convergence of the registration task. (2) A domain adaptation module reduces the domain gap between the x-ray image and digitally reconstructed radiograph projected from the CT volume, decreasing the sensitivity and uncertainty of the similarity measurement. (3) A weighted reward function facilitates CT2X-IRA in searching for the optimal transformation parameters, improving the estimation accuracy of out-of-plane transformation parameters under large initial misalignments.Main results.We evaluate the proposed CT2X-IRA on both the public and private clinical datasets, achieving target registration errors of 2.13 mm and 2.33 mm with the computation time of 1.5 s and 1.1 s, respectively, showing an accurate and fast workflow for CT/x-ray image rigid registration.Significance.The proposed CT2X-IRA obtains the accurate and robust 3D/2D registration of CT and x-ray images, suggesting its potential significance in clinical applications.

SrB4O7:Sm2+ fluorescence improves the accuracy of temperature measurements in externally heated diamond anvil cells

The sample temperature in an externally heated diamond anvil cell (EHDAC) is generally measured by a thermocouple fixed to the pavilions of diamond anvils, ignoring the temperature difference between the thermocouple and the sample. However, the measured temperature depends strongly on the placement of the thermocouple, thus seriously reducing the accuracy of the temperature measurement and hindering the use of EHDAC in experiments requiring precise temperature measurements, such as high-pressure melting and phase-diagram investigations. In this study, the full width at half maximum (FWHM) of the 0-0 fluorescence line of strontium borate doped with bivalent samarium ions (SrBO₄:Sm²⁺, SBO) is found to be highly sensitive to temperature and responds extremely rapidly to small temperature fluctuations, which makes it an excellent temperature indicator. We propose herein a precise method to measure temperature that involves measuring the FWHM of the 0-0 fluorescence line of SBO. This method is used to correct the temperature discrepancy between the thermocouple and the sample in an EHDAC. These corrections significantly improve the accuracy of temperature measurements in EHDACs. The accuracy of this method is verified by measuring the melting point of tin at ambient pressure. We also use this method to produce a tentative elementary phase diagram of tin up to 109 GPa and 495 K. This method facilitates high-pressure, high-temperature experiments demanding accurate temperature measurements in various disciplines. The study also discusses, in general, the experimental approach to measuring temperature.

["Identifying forms and verifying quality" in materia medica]

The thinking of "identifying forms and verifying quality'' in materia medica research came from the theory of "treatment based on syndrome differentiation" in traditional Chinese medicine. It refers to an approach to evaluate the quality of materia medica based on their characteristics and external properties in order to clarify the nature of medicinal materials. This paper examined the historical development of "identifying forms and verifying quality'' from the pre-Qin Dynasty up to today and analysed the connotation of this thinking. It is believed that this thinking has advantages such as scientific, holistic, practical, and universal considerations. However, it still needs to be developed in terms of philosophical thinking and practical application.

[The illustrations in the works of traditional Chinese medicine in the period of the Republic of China: indicating the integrated thinking of Chinese and western medicine]

Some works of traditional Chinese medicine in the period of the Republic of China were influenced by the integrated thinking of Chinese and Western medicine to some extent. This was reflected in the illustrations in the works of the time. A total of 1,932 illustrations or diagrams found in sixteen institution's book collections in China illustrated the integration of medical thinking. The illustrations and diagrams were classified into eleven categories. The categories were theoretical illustration, medical charts, viscera diagrams, disease diagrams, acupoint diagrams, apparatus diagrams, human body diagrams, fetal birth charts, drug diagrams, figure pictures, and experimental diagrams. It was found that these illustrations or diagrams had their own characteristics at the time and greatly influenced anatomy. However, the author has argued that most of the influence was on the surface.

Augmented reality calibration using feature triangulation iteration-based registration for surgical navigation

BACKGROUND

Marker-based augmented reality (AR) calibration methods for surgical navigation often require a second computed tomography scan of the patient, and their clinical application is limited due to high manufacturing costs and low accuracy.

METHODS

This work introduces a novel type of AR calibration framework that combines a Microsoft HoloLens device with a single camera registration module for surgical navigation. A camera is used to gather multi-view images of a patient for reconstruction in this framework. A shape feature matching-based search method is proposed to adjust the size of the reconstructed model. The double clustering-based 3D point cloud segmentation method and 3D line segment detection method are also proposed to extract the corner points of the image marker. The corner points are the registration data of the image marker. A feature triangulation iteration-based registration method is proposed to quickly and accurately calibrate the pose relationship between the image marker and the patient in the virtual and real space. The patient model after registration is wirelessly transmitted to the HoloLens device to display the AR scene.

RESULTS

The proposed approach was used to conduct accuracy verification experiments on the phantoms and volunteers, which were compared with six advanced AR calibration methods. The proposed method obtained average fusion errors of 0.70 ± 0.16 and 0.91 ± 0.13 mm in phantom and volunteer experiments, respectively. The fusion accuracy of the proposed method is the highest among all comparison methods. A volunteer liver puncture clinical simulation experiment was also conducted to show the clinical feasibility.

CONCLUSIONS

Our experiments proved the effectiveness of the proposed AR calibration method, and revealed a considerable potential for improving surgical performance.

Engineering topological states in atom-based semiconductor quantum dots

The realization of controllable fermionic quantum systems via quantum simulation is instrumental for exploring many of the most intriguing effects in condensed-matter physics^1–3. Semiconductor quantum dots are particularly promising for quantum simulation as they can be engineered to achieve strong quantum correlations. However, although simulation of the Fermi–Hubbard model⁴ and Nagaoka ferromagnetism⁵ have been reported before, the simplest one-dimensional model of strongly correlated topological matter, the many-body Su–Schrieffer–Heeger (SSH) model^6–11, has so far remained elusive—mostly owing to the challenge of precisely engineering long-range interactions between electrons to reproduce the chosen Hamiltonian. Here we show that for precision-placed atoms in silicon with strong Coulomb confinement, we can engineer a minimum of six all-epitaxial in-plane gates to tune the energy levels across a linear array of ten quantum dots to realize both the trivial and the topological phases of the many-body SSH model. The strong on-site energies (about 25 millielectronvolts) and the ability to engineer gates with subnanometre precision in a unique staggered design allow us to tune the ratio between intercell and intracell electron transport to observe clear signatures of a topological phase with two conductance peaks at quarter-filling, compared with the ten conductance peaks of the trivial phase. The demonstration of the SSH model in a fermionic system isomorphic to qubits showcases our highly controllable quantum system and its usefulness for future simulations of strongly interacting electrons.

Precision-engineered devices consisting of a linear array of ten quantum dots are used to realize both the trivial and topological phases of the many-body Su–Schrieffer–Heeger model.

Radiotherapy Standardisation and Artificial Intelligence within the National Cancer Institute's Clinical Trials Network

Artificial intelligence in healthcare refers to the use of complex algorithms designed to conduct certain tasks in an automated manner. Artificial intelligence has a transformative power in radiation oncology to improve the quality and efficiency of patient care, given the increase in volume and complexity of digital data, as well as the multi-faceted and highly technical nature of this field of medicine. However, artificial intelligence alone will not be able to fix healthcare's problem, because new technologies bring unexpected and potentially underappreciated obstacles. The inclusion of multicentre datasets, the incorporation of time-varying data, the assessment of missing data as well as informative censoring and the addition of clinical utility could significantly improve artificial intelligence models. Standardisation plays a crucial, supportive and leading role in artificial intelligence. Clinical trials are the most reliable method of demonstrating the efficacy and safety of a treatment or clinical approach, as well as providing high-level evidence to justify artificial intelligence. The National Surgical Adjuvant Breast and Bowel Project, the Radiation Therapy Oncology Group and the Gynecologic Oncology Group collaborated to form NRG Oncology (acronym NRG derived from the names of the parental groups). NRG Oncology is one of the adult cancer clinical trial groups containing radiotherapy specialty of the National Cancer Institute's Clinical Trials Network (NCTN). Standardisation from NRG/NCTN has the potential to reduce variation in clinical treatment and patient outcome by eliminating potential errors, enabling broader application of artificial intelligence tools. NCTN, NRG and Imaging and Radiation Oncology Core are in a unique position to help with standards development, advocacy and enforcement, all of which can benefit from artificial intelligence, as artificial intelligence has the ability to improve trial success rates by transforming crucial phases in clinical trial design, from study planning through to execution. Here we will examine: (i) how to conduct technical and clinical evaluations before adopting artificial intelligence technologies, (ii) how to obtain high-quality data for artificial intelligence, (iii) the NCTN infrastructure and standards, (iv) radiotherapy standardisation for clinical trials and (v) artificial intelligence applications in standardisation.

[Effects of regional citrate anticoagulation in continuous veno-venous hemofiltration of severe burn patients]

Objective: To investigate the effects of regional citrate anticoagulation in continuous veno-venous hemofiltration (CVVH) of severe burn patients. Methods: A retrospective non-randomized controlled study was conducted. From January 2017 to August 2020, sixty-eight severe burn patients who met the inclusion criteria were treated with CVVH in Affiliated Hospital of Nankai University. According to the different methods of blood anticoagulation in CVVH treatment, patients were divided into citrate group (n=40) and heparin group (n=28). In the citrate group, 32 males and 8 females were (40±18) years old with total burn area of (62±14)% total body surface area (TBSA); in the heparin group, 22 males and 6 females were (38±16) years old with total burn area of (57±20)%TBSA. Creatinine level, C-reactive protein (CRP) value, and urea nitrogen level in serum of patients were recorded at 0 (immediately), 48, and 96 h after CVVH treatment in 2 groups, urea clearance index was calculated based on urea nitrogen level at 0, 48, and 96 h after CVVH treatment in 2 groups, platelet count (PLT), prothrombin time (PT), and activated partial thromboplastin time (APTT) in total coagulation of patients were recorded. The frequency of forced hemofiltration termination caused by adverse reactions such as severe hypocalcemia, aggravated wound bleeding, and new bleeding on non-wound surface of patients was recorded within 96 h of CVVH treatment. The duration of daily CVVH use from the beginning to the end was recorded. Data were statistically analyzed with chi-square test, analysis of variance for repeated measurement, independent samples t test, and Bonferroni correction. Results: There were no significant differences in urea nitrogen level, creatinine level, and CRP value in serum of patients between 2 groups at 0 h after treatment (P>0.05). At 48 and 96 h after treatment, urea nitrogen level, creatinine level, and CRP value in serum of patients in citrate group were significantly lower than those in heparin group (t=3.366, -2.315, 2.942, -2.657, 2.011, -2.441, P<0.05), and urea clearance index of patients in citrate group was significantly higher than that in heparin group (t=1.017, 2.233, P<0.05). There were no statistically significant differences in PLT, PT, and APTT of patients between 2 groups at 0 h after treatment (P>0.05). At 48 and 96 h, PLT of patients in citrate group was significantly higher than that in heparin group (t=-3.417, -4.143, P<0.05 or P<0.01), PT of patients in citrate group was significantly shorter than that in heparin group (t=2.760, -3.655, P<0.01), APTT of patients in citrate group was significantly shorter than that in heparin group (t=3.719, 5.146, P<0.05 or P<0.01). Within 96 h of treatment, there was 1 case of hypocalcemia and 1 case of aggravated wound bleeding resulting in forced hemofiltration termination in citrate group, but there was no new bleeding on non-wound surface; in heparin group, there was no hypocalcemia, but 7 cases of aggravated wound bleeding and 2 cases of new bleeding on non-wound surface (both at the tracheotomy site) resulting in forced hemofiltration termination. The use time of blood purification filter of patients in citrate group was (11.7±4.8) h, obviously longer than (6.6±2.5) h in heparin group (t=3.310, P<0.01). Conclusions: The use of regional citrate anticoagulation in CVVH treatment of severe burn patients has the advantages including little effect on coagulation function and high safety, can effectively prolong the use time of filter and improve the therapeutic effect, but this conclusion still needs to be further verified in clinical application.

[A new classification of intrahepatic cholangiocarcinoma based on actual anatomy:a series of 135 cases]

Objective: To explore the feasibility and clinical value of a new classification for resectable intrahepatic cholangiocarcinoma (IHCC) according to the actual anatomy. Methods: The data of 135 patients with IHCC who were admitted to the Department of Hepatopancreatobiliary Surgery,Second Affiliated Hospital of Zhejiang University School of Medicine from November 2011 to November 2020 after discussion by a multidisciplinary team and planned to undergo radical resection were analyzed retrospectively. There were 77 males and 58 females,with a median age of 61 years (range:26 to 86 years),of which 38 cases had vascular invasion. This new classification was carried out independently by two hepatobiliary surgeons. First,a preliminary classification was made based on the location of the tumor,and then the final classification was based on vascular invasion. All patients were followed up by telephone,and the follow-up was as of November 2020. Survival time is defined as the time after surgery to follow-up or death. Log-rank test was used to compare patients' median recurrence-free survival and overall survival time. The Cox proportional hazard model was used to analyze the prognosis factors of the overall survival time of patients with IHCC. Results: Among the 135 patients,129 underwent R0 resection and 6 underwent R1 resection. According to the actual anatomy,28 cases (20.7%) belonged to segmental type, 43 cases (31.9%) belonged to branch type, 64 cases (47.4%). The median survival time of all patients was 35.2 months(95%CI:21.3 to 70.5 months),the 1-year cumulative survival rate was 75.1%,the 3-year cumulative survival rate was 45.8%,and the 5-year cumulative survival rate was 39.0%. After grouping according to the classification,the median survival time of segmental patients was 36.9 months (more than 50% of patients reached the median survival time),and the median survival time of branched patients was 33.8 months (95%CI:16.8 to 38.5);The median survival time of lobe patients was 25.0 months (95%CI:13.6 to 58.7). The result of Log-rank test between groups indicated that the median survival time of patients with segmental type was better than that of patients with branch and lobe type(HR=2.03,95%CI:1.24 to 3.64,P=0.006);There was no significant difference in survival time between patients with branch type and lobe type (P=0.685). The results of the multivariate analysis of the Cox risk ratio model suggested that the actual anatomical location classification (HR=2.32,95%CI:1.10 to 4.92,P=0.028) and the postoperative lymph node metastasis rate (HR=2.06,95%CI:1.24 to 3.45,P=0.005) were independent factors related to survival after radical resection of IHCC patients. Conclusion: It is simple and convenient to classify resectable IHCC by actual anatomy,which can be used to preliminarily judge the prognosis of patients and provide a feasible classification scheme for the clinic.

Comparison of modeling accuracy between Radixact®and CyberKnife®Synchrony®respiratory tracking system

Synchrony Respiratory Tracking system adapted from CyberKnife has been introduced in Radixact to compensate the tumor motion caused by respiration. This study aims to compare the modeling accuracy of the Synchrony system between Radixact and CyberKnife. Two Synchrony plans based on fiducial phantoms were created for CyberKnife and Radixact, respectively. Different respiratory motion traces were used to drive a motion platform to move along the superoinferior and left-right direction. The cycle time and the amplitude of target/surrogate motion of one selected motion trace were scaled to investigate the dependence of modeling accuracy on the motion characteristic. The predicted target position, the correlation error, potential difference (Radixact only) and standard error (CyberKnife only) were extracted from raw data or log files of the two systems. The modeling accuracy was evaluated by calculating the root-mean-square (RMS) error between the predicted target positions and the input motion trace. A threshold T95 within which 95% of the potential difference or the standard error lay was defined and evaluated. Except for the motion trace with a small amplitude and a good (linear) correlation between target and surrogate motion, Radixact showed smaller RMS errors than CyberKnife. The RMS error of both systems increased with the motion amplitude and showed a decreasing trend with the increasing cycle time. No correlation was found between the RMS error and the amplitude of surrogate motion. T95 could be a good estimator of modeling accuracy for CyberKnife rather than Radixact. The correlation error defined in Radixact were largely affected by the number of fiducial markers and the setup error. In general, the modeling accuracy of the Radixact Synchrony system is better than that of the CyberKnife Synchrony system under unfavorable conditions.

Initial clinical experience of patient-specific QA of treatment delivery in online adaptive radiotherapy using a 1.5 T MR-Linac

Purpose. This study aims to evaluate the performance of a commercial 1.5 T MR-Linac by analyzing its patient-specific quality assurance (QA) data collected during one full year of clinical operation.Methods and Materials. The patient-specific QA system consisted of offline delivery QA (DQA) and online calculation-based QA. Offline DQA was based on ArcCHECK-MR combined with an ionization chamber. Online QA was performed using RadCalc that calculated and compared the point dose calculation with the treatment planning system (TPS). A total of 24 patients with 189 treatment fractions were enrolled in this study. Gamma analysis was performed and the threshold that encompassed 95% of QA results (T95) was reported. The plan complexity metric was calculated for each plan and compared with the dose measurements to determine whether any correlation existed.Results. All point dose measurements were within 5% deviation. The mean gamma passing rates of the group data were found to be 96.8 ± 4.0% and 99.6 ± 0.7% with criteria of 2%/2mm and 3%/3mm, respectively. T95 of 87.4% and 98.2% was reported for the overall group with the two passing criteria, respectively. No statistically significant difference was found between adaptive treatments with adapt-to-position (ATP) and adapt-to-shape (ATS), whilst the category of pelvis data showed a better passing rate than other sites. Online QA gave a mean deviation of 0.2 ± 2.2%. The plan complexity metric was positively correlated with the mean dose difference whilst the complexity of the ATS cohort had larger variations than the ATP cohort.Conclusions. A patient-specific QA system based on ArcCHECK-MR, solid phantom and ionization chamber has been well established and implemented for validation of treatment delivery of a 1.5 T MR-Linac. Our QA data obtained over one year confirms that good agreement between TPS calculation and treatment delivery was achieved.

[The expression of VHL/HIF signaling pathway in the erythroid progenitor cells with chronic mountain sickness]

Objective: To investigate the expression and interaction of VHL/HIF-α pathways including HIF-1α, HIF-2α as well as VHL in erythroid progenitor cells of bone marrow from chronic mountain sickness (CMS) patients. Methods: A total of 25 patients with CMS and 21 healthy controls were recruited for this study. The CD71(+)CD235a(+) cells in bone marrow mononuclear cells, marked as erythroid progenitor cells, were isolated using MACS separation technology. The expression levels of HIF-1α, HIF-2α and VHL in erythroid progenitor cells were detected by Western blotting and real-time fluorescence quantitative PCR. Results: The mRNA levels of HIF-2α were higher in erythroid progenitor cells of CMS than in healthy controls [1.68 (0.81, 2.22) vs 0.98 (0.60, 1.19), P<0.05], while HIF-1α and VHL mRNA levels were similar between the two groups (P>0.05). Spearman analyses indicated that HIF-2α mRNA was positively associated with hemoglobin (Hb) levels in the erythroid progenitor cells of CMS (ρ=0.504, P<0.05). Furthermore, the mRNA level of HIF-2α was correlated with the mRNA level of VHL in the erythroid progenitor cells of CMS (ρ=0.647, P<0.05).The protein levels of HIF-2α in the erythroid progenitor cells of CMS were higher than that of healthy controls [0.94(0.68, 3.30) vs 0.59(0.30, 0.88), P<0.05], but the protein levels of HIF-1α and VHL were similar between the two groups (P>0.05). Conclusions: The abnormal increased expression of HIF-2α in the erythroid progenitor cells of CMS patients leads to the abnormal expression of hypoxia sensitive genes downstream, participating in the occurrence and development of CMS.

[Influence of directed restrictive fluid management strategy on patients with serious burns complicated by severe inhalation injury]

Objective: To explore the influence of directed restrictive fluid management strategy (RFMS) on patients with serious burns complicated by severe inhalation injury. Methods: Sixteen patients with serious burns complicated by severe inhalation injury hospitalized in our department from December 2014 to December 2017, meeting the inclusion criteria and treated with RFMS, were enrolled in directed treatment group. Thirty-four patients with serious burns complicated by severe inhalation injury hospitalized in our department from December 2012 to December 2017, meeting the inclusion criteria and without RFMS, were enrolled in routine treatment group. Medical records of patients in 2 groups were retrospectively analyzed. Within post injury day 2, mean arterial pressure (MAP), central venous pressure (CVP), extravascular lung water index (ELWI), global end-diastolic volume index, and pulmonary vascular permeability index of patients in directed treatment group were monitored by pulse contour cardiac output monitoring technology, while MAP and CVP of patients in routine treatment group were monitored by routine method. On post injury day 3 to 7, patients in 2 groups were treated with routine fluid supplement therapy of our Department to maintain hemodynamic stability, and patients in directed treatment group were treated according to RFMS directed with goal of ELWI≤7 mL·kg(-1)·m(-2). On post injury day 3 to 7, total fluid intake, total fluid output, and total fluid difference between fluid intake and output within 24 h, value of blood lactic acid, and oxygenation index of patients in 2 groups were recorded. Occurrence of acute respiratory distress syndrome (ARDS) on post injury day 3 to 7 and 8 to 28, mechanical ventilation time within post injury day 28, and occurrence of death of patients in 2 groups were counted. Data were processed with chi-square test, t test, and analysis of variance for repeated measurement. Results: The total fluid intakes within 24 h of patients in directed treatment group were close to those in routine treatment group on post injury day 3, 4, 5, 6, 7 (t=-0.835, -1.618, -2.463, -1.244, -2.552, P>0.05). The total fluid outputs and total fluid differences between fluid intake and output within 24 h of patients in 2 groups on post injury day 3 were close (t=0.931, -2.274, P>0.05). The total fluid outputs within 24 h of patients in directed treatment group were significantly higher than those in routine treatment group on post injury day 4, 5, 6, 7 (t=2.645, 2.352, 1.847, 1.152, P<0.05). The total fluid differences between fluid intake and output within 24 h of patients in directed treatment group were (2 928±768), (2 028±1 001), (2 186±815), and (2 071±963) mL, significantly lower than (4 455±960), (3 434±819), (3 233±1 022), and (3 453±829) mL in routine treatment group (t=-4.331, -3.882, -3.211, -4.024, P<0.05). The values of blood lactic acid of patients in directed treatment group and routine treatment group on post injury day 3, 4, 5, 6, 7 were close (t=0.847, 1.221, 0.994, 1.873, 1.948, P>0.05). The oxygenation indexes of patients in directed treatment group on post injury day 3 and 4 were (298±78) and (324±85) mmHg (1 mmHg=0.133 kPa ), which were close to (270±110) and (291±90) mmHg in routine treatment group (t=-1.574, 2.011, P>0.05). The oxygenation indexes of patients in directed treatment group on post injury day 5, 6, 7 were (372±88), (369±65), and (377±39) mmHg, significantly higher than (302±103), (313±89), and (336±78) mmHg in routine treatment group (t=3.657, 3.223, 2.441, P<0.05). On post injury day 3, 4, 5, 6, 7, patients with ARDS in directed treatment group were less than those in routine treatment group, but with no significantly statistical difference between the 2 groups (χ(2)=0.105, P>0.05). On post injury day 8 to 28, patients with ARDS in directed treatment group were significantly less than those in routine treatment group (χ(2)=0.827, P<0.05). The mechanical ventilation time within post injury day 28 of patients in directed treatment group was apparently shorter than that in routine treatment group (t=-2.895, P<0.05). Death of patients in directed treatment group within post injury day 28 was less than that in routine treatment group, but with no significantly statistical difference between the 2 groups (χ(2)=0.002, P>0.05). Conclusions: Under the circumstance of hemodynamics stability, RFMS directed with goal of ELWI≤7 mL·kg(-1)·m(-2) on post injury day 3 to 7 is an useful strategy, which can reduce occurrence rate of ADRS and shorten mechanical ventilation time of patients with serious burns complicated by severe inhalation injury at late stage of burns.

[Analysis on the characteristics of postural blood pressure changes recorded with continuous non-invasive arterial pressure monitoring system and the correlative factors in elderly hospitalized patients]

Objective: To explore the characteristics of postural blood pressure changes in elderly inpatients and the related factors of orthostatic hypotension (OH). Methods: This study was a clinical case control study. Two hundred and sixty-six elderly patients (≥60 years old), who were hospitalized between April 2016 and November 2017 in Geriatric Department of Peking University First Hospital, were included. They were divided into direct standing group and indirect standing group. Direct standing group involved 102 patients, they changed posture from supine directly to standing position, and the blood pressures at the moments of supine, immediately after standing and the first, second, and third minute after standing were recorded by continuous noninvasive arterial pressure (CNAP) system. Indirect standing group involved 164 patients, and they changed posture from supine to sitting for 3 minutes, and then changed to standing position. Blood pressures at the moments of supine, immediately after sitting, the third minute after sitting, immediately after standing and the third minute after standing was recorded by CNAP. Blood pressure changes after different postural changes mode and the rates of OH were compared. The related factors of OH was analyzed by binary logistic regression analysis. Results: The lowest systolic blood pressures (SBP) mostly occurred immediately after postural change: immediately after standing for direct standing group (86.3%(88/102)), and immediately after sitting for indirect standing group (59.1%(97/164)). The lowest diastolic blood pressures (DBP) mostly occurred immediately after standing in the two groups: 87.3%(89/102) for direct standing group and 43.3% (71/164) for indirect standing group. The maximum SBP drop (SBP of supine minus the lowest SBP during postural changes) of direct standing group was significantly higher than indirect standing group (median 20.5(14.0, 29.3) vs. 18.0(11.0, 26.0) mmHg (1 mmHg=0.133 kPa, P<0.05). The rates of OH occurred immediately and within 3 minutes from supine to standing position were significantly higher in direct standing group than in indirect standing group (65.7% (67/102) vs. 43.9% (72/164), and 70.6% (72/102) vs. 49.4% (81/164), both P<0.05). Binary logistic regression analysis showed that brachial-ankle pulse wave velocity was positively associated with OH after a transition from supine to standing position (immediately and within 3 minutes, OR=1.002 (95%CI 1.000-1.004), 1.003 (95%CI 1.001-1.006), P=0.014, 0.006) in direct standing group. Conclusions: OH is common in elderly hospitalized patients. The most obvious blood pressure changes are likely to occur immediately after position changes. Adding a sitting position during the transition of supine to standing position may decrease the amplitude of SBP drop. Brachial-ankle pulse wave velocity is associated with OH after the transition from the supine to standing position in the elderly inpatients.

[Types and characteristics of advertising images in Chinese medicine works during the Republic of China]

The emergence of advertising images in Chinese medicine works during the period of China is the inevitable outcome of the development of commercial society. In the 237 advertising images, there are 106 pictures, 130 ink lines and 1 color photograph. It can be divided into 8 categories: chemist's shop, hospital, medical products, Chinese medicine school and organizations, book, book publishers, commodity and public service. It can reflect the popular themes of the society and social atmosphere at that time, having vivid characteristics of the times and artistry. Advertising image is a unique phenomenon in the books of the Republic of China.

[The expressions of VEGF and VEGFR signaling pathway in the bone marrow mononuclear cells with chronic mountain sickness]

Objective: This study was aimed at investigating the levels and relationships of vascular endothelial growth factor (VEGF) and its receptor(VEGFR) in the bone marrow mononuclear cells (MNC) of chronic mountain sickness (CMS). Methods: A total of 34 patients with CMS and 30 controls residing at altitudes of 3 000-4 500 m were recruited for this study. The levels of VEGF, VEGFR1 and VEGFR2 in bone marrow MNC were detected by flow cytometry technique and RT-qPCR. Results: The percentage of VEGFR2 positive cells in the bone marrow MNC of CMS were higher than that of the controls[20.7% (8.1%, 67.6%) vs 8.1% (2.2%, 14.9%), P<0.05], but that of VEGFR1-positive and VEGF-positive were similar in CMS and controls. The mRNA levels of VEGFR2 were higher in the bone marrow MNC of CMS than in the controls[1.7(1.0, 5.1) vs 1.0(0.4, 2.7), P<0.05], while VEGF and VEGFR1 mRNA levels were similar between the two groups. The percentage of VEGFR2 positive cells in CMS were significantly correlated with hemoglobin (r=0.453, P=0.007) and the percentage of VEGF-positive cells (r=0.373, P=0.030). Conclusions: Bone marrow MNC of CMS may show enhanced activity of the VEGF-VEGFR2 pathway, and it appears to be involved in the pathogenesis of CMS.

Theory of Inverse Edelstein Effect of The Surface States of A Topological Insulator

The surface states of three-dimensional topological insulators possess the unique property of spin-momentum interlocking. This property gives rise to the interesting inverse Edelstein effect (IEE), in which an applied spin bias μ is converted to a measurable charge voltage difference V. We develop a semiclassical theory for the IEE of the surface states of Bi2Se3 thin films, which is applicable from the ballistic regime to diffusive regime. We find that the efficiency of the spin-charge conversion, defined as γ = V/μ, exhibits a universal dependence on the ratio between sample size and electron mean free path. The efficiency increases from γ = π/4 in the ballistic limit to γ = π in the diffusive limit, suggesting that sufficient strength of impurity scattering is favorable for the IEE.

Filmless methods for quality assurance of Tomotherapy using ArcCHECK

PURPOSE

Tomotherapy delivers an intensity-modulated radiation therapy (IMRT) treatment by the synchronization of gantry rotation, multileaf collimator (MLC), and couch movement. This dynamic nature makes the quality assurance (QA) important and challenging. The purpose of this study is to develop some methodologies using an ArcCHECK for accurate QA measurements of the gantry angle and speed, MLC synchronization and leaf open time, couch translation per gantry rotation, couch speed and uniformity, and constancy of longitudinal beam profile for a Tomotherapy unit.

METHODS

Four test plans recommended by AAPM Task Group 148 (TG148) and the manufacturer were chosen for this study. Helical and static star shot tests are used for checking the leaves opened at the expected gantry angles. Another helical test is to verify the couch traveled the expected distance per gantry rotation. The final test is for checking the couch speed constancy with a static gantry. ArcCHECK can record the detector signal every 50 ms as a movie file, and has a virtual inclinometer for gantry angle measurement. These features made the measurement of gantry angle and speed, MLC synchronization and leaf open time, and longitudinal beam profile possible. A shaping parameter was defined for facilitating the location of the beam center during the plan delivery, which was thereafter used to calculate the couch translation per gantry rotation and couch speed. The full width at half maximum (FWHM) was calculated for each measured longitudinal beam profile and then used to evaluate the couch speed uniformity. Furthermore, a mean longitudinal profile was obtained for constancy check of field width. The machine trajectory log data were also collected for comparison. Inhouse programs were developed in MATLAB to process both the ArcCHECK and machine log data.

RESULTS

The deviation of our measurement results from the log data for gantry angle was calculated to be less than 0.4°. The percentage differences between measured and planned leaf open time were found to be within 0.5% in all the tests. Our results showed mean values of MLC synchronization of 0.982, 0.983, and 0.995 at static gantry angle 0°, 45°, and 135°, respectively. The mean value of measured couch translation and couch speed by ArcCHECK had less than 0.1% deviation from the planned values. The variation in the value of FWHM suggested the couch speed uniformity was better than 1%. The mean of measured longitudinal profiles was suitable for constancy check of field width.

CONCLUSION

Precise and efficient methods for measuring the gantry angle and speed, leaf open time, couch translation per gantry rotation, couch speed and uniformity, and constancy of longitudinal beam profile of Tomotherapy using ArcCHECK have been developed and proven to be accurate compared with machine log data. Estimation of the Tomotherapy binary MLC leaf open time is proven to be precise enough to verify the leaf open time as small as 277.8 ms. Our method also makes the observation and quantification of the synchronization of leaves possible.

[Spatial-temporal analysis of pulmonary tuberculosis in Shandong province, 2015]

Objective: To analyze the spatial-temporal epidemiological characteristics of active pulmonary tuberculosis (PTB) and sputum smear positive (SS+) PTB in Shandong province, China, 2015. Methods: The surveillance data of active PTB and SS+PTB in Shandong in 2015 were collected and analyzed by using the global and local indicators of spatial association (Moran's I) for the spatial autocorrelation of PTB, and by using SaTScan forspatial-temporal clustering characteristics of PTB based on geographic information system. Results: Totally, 31 776 active PTB cases and 8 631 SS+PTB cases were reported in Shandong in 2015, and the reported incidence rates of active PTB and SS+PTB were 33.09/100 000 and 8.99/100 000, respectively. Active PTB had positive spatial autocorrelation at county level, and the value of Moran's I value was 0.219 (P<0.001), indicating that the high-high (HH) aggregation areas with high incidence were in the northwestern, southeastern and central southern Shandong; SS+PTB also had positive spatial autocorrelation at county level, and the value of the Moran's I was 1.178 (P<0.001), indicating that the HH aggregation areas with high incidence were in the southeastern and northwestern Shandong. The results of spatial-temporal scanning indicated that there was incidence clustering of active PTB in the second quarter and the third quarter in 2015, and the clustering areas were in the central southern, southeastern and northwestern Shandong; there also was incidence clustering of SS+PTB in the second quarter and the third quarter in 2015, and the clustering areas were in the southeastern and northwestern Shandong. Conclusions: The incidence of active PTB and SS+PTB showed spatial and temporal clustering in Shandong in 2015. The areas with high PTB burden and high PTB transmission risks were in the northwestern and southeastern Shandong. The areas with high PTB burden but without high PTB transmission risks were in the central southern Shandong.