Numerical investigation on characteristics of vortex dissipation in multi-horizontal submerged jets stilling basin.

Multi-horizontal submerged jets stilling basins have been utilized in large-scale water conservancy and hydropower projects due to its stable flow pattern, high energy dissipation rate and less atomization. This study employs vorticity criterion, Q criterion, λ2 criterion and Ω criterion to investigate the characteristics of vortex formation and turbulent dissipation in multi-horizontal submerged jets stilling basins with various configurations, including crest overflowing orifice alone (COO), combination of crest overflowing orifice and mid-discharge orifice (COO-MO) and mid-discharge orifice alone (MO). The results indicate that the Q criterion and λ2 criterion are effective in identifying vortex structure within multi-horizontal submerged jets stilling basin. Specifically, the stronger intensity of vortex structure and vortex dissipation are mainly distributed in the vicinity of the vertical drop, which gradually weakens for the increasing distance to the vertical drop. Furthermore, the intensity and number of vortexes with COO-MO are the largest. This conclusion can provide guidance for energy dissipation and bottom protection of stilling pool.

Al18F-NOTA-Octreotide outperforms 18F-FDG in identifying rare renal metastases from pancreatic neuroendocrine tumor.

We presented a case involving a 56-year-old man who had been experiencing shoulder and back pain for over a year, with extensive bone metastases revealed by a bone scan. To identify the primary source of these issues, the patients underwent a fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) scan, which indicated moderate uptake in the right renal soft mass and low uptake in multiple osteolytic lesions. Pathological examination and immunohistochemical staining of the renal mass supported the diagnosis of neuroendocrine tumors. Subsequently, a novel somatostatin receptor imaging agent, Al18F-NOTA-octreotide (18F-OC), was performed to further investigate the source of metastatic lesions and to stage the tumor. The 18F-OC scan revealed a high-uptake lesion in the pancreatic head, as well as additional lymph node and bone metastases lesions. Compared to 18F-FDG, the 18F-OC demonstrated superior imaging capabilities and a significantly higher tumor-to-background ratio in neuroendocrine neoplasms, which contributed to improving the staging and treatment management.

Prediction of cervical lymph node metastasis in differentiated thyroid cancer based on radiomics models.

OBJECTIVE: The accurate clinical diagnosis of cervical lymph node metastasis plays an important role in the treatment of differentiated thyroid cancer (DTC). This study aimed to explore and summarize a more objective approach to detect cervical malignant lymph node metastasis of DTC via radiomics models. METHODS: PubMed, Web of Science, MEDLINE, EMBASE, and Cochrane databases were searched for all eligible studies. Articles using radiomics models based on ultrasound, computed tomography, or magnetic resonance imaging to assess cervical lymph node metastasis preoperatively were included. Characteristics and diagnostic accuracy measures were extracted. Bias and applicability judgments were evaluated by the revised QUADAS-2 tool. The estimates were pooled using a random-effects model. Additionally, the leave-one-out method was conducted to assess the heterogeneity. RESULTS: Twenty-nine radiomics studies with 6160 validation set patients were included in the qualitative analysis, and 11 studies with 3863 validation set patients were included in the meta-analysis. Four of them had an external independent validation set. The studies were heterogeneous, and a significant risk of bias was found in 29 studies. Meta-analysis showed that the pooled sensitivity and specificity for preoperative prediction of lymph node metastasis via US-based radiomics were 0.81 (95% CI, 0.73-0.86) and 0.87 (95% CI, 0.83-0.91), respectively. CONCLUSIONS: Although radiomics-based models for cervical lymphatic metastasis in DTC have been demonstrated to have moderate diagnostic capabilities, broader data, standardized radiomics features, robust feature selection, and model exploitation are still needed in the future. ADVANCES IN KNOWLEDGE: The radiomics models showed great potential in detecting malignant lymph nodes in thyroid cancer.

Effect of cognitive behavior therapy based on the health education pathway on psychology of papillary thyroid carcinoma patients: a randomized controlled trial.

OBJECTIVES: Our main aim was to explore whether cognitive behavior therapy based on the health education pathway (CBT-HEP) can effectively alleviate the distress, anxiety, and depression of papillary thyroid carcinoma (PTC) patients after 131 I treatment. In addition, we investigated the critical factors that can significantly affect the distress and quality of life in PTC patients before 131 I treatment. METHODS: In total, 496 people were screened and 357 were enrolled, followed by randomization of those with a distress thermometer (DT) ≥4. Patients in the experimental group received CBT-HEP intervention, and patients in the control group were given casual conversation. RESULTS: The scores of DT, Hamilton Anxiety Scale (HAMA) and Patient Health Questionnaire-9 (PHQ-9) in CBT-HEP group decreased gradually after intervention. In control group, DT scores decreased significantly, while HAMA and PHQ-9 scores did not change significantly. CONCLUSION: CBT-HEP is effective in relieving distress, anxiety and depression in PTC patients. In addition, female sex, lifestyle, hypothyroidism, negative emotions, related symptoms, fear of tumor recurrence and radiation safety are the critical factors affecting mental health and quality of life.

Case Report: a rare primary gastric choriocarcinoma revealed on 18F-FDG PET/CT.

Choriocarcinoma is an exceptionally aggressive trophoblastic cell tumor that that typically originates in gonadal tissues, with rare occurrences outside the gonads, including the mediastinum, retroperitoneum, and intracranial sites. However, it rarely occurs in the stomach. Herein, we presented a case of primary gastric choriocarcinoma in a 27-year-old female patient who found multiple liver masses detected during physical examination, accompanied by remarkably elevated human chorionic gonadotropin levels. The 18F-FDG PET/CT scan suggested ring-shaped intense uptake masses located in the gastric sinus and liver, and no significance in the pelvic region. Final histopathology indicated primary choriocarcinoma of the stomach. This case illustrates that 18F-FDG PET/CT is an essential imaging technique for the clinical diagnosis and stage of primary choriocarcinoma.

Prognostic significance and postoperative chemoradiotherapy guiding value of mean platelet volume for locally advanced esophageal squamous cell carcinoma patients.

Objective: To investigate the predicting prognosis and guiding postoperative chemoradiotherapy (POCRT) value of preoperative mean platelet volume (MPV) in patients with locally advanced esophageal squamous cell carcinoma (LA-ESCC). Methods: We proposed a blood biomarker, MPV, for predicting disease-free survival (DFS) and overall survival (OS) in LA-ESCC patients who underwent surgery (S) alone or S+POCRT. The median cut-off value of MPV was 11.4 fl. We further evaluated whether MPV could guide POCRT in the study and external validation groups. We used multivariable Cox proportional hazard regression analysis, Kaplan-Meier curves, and log-rank tests to ensure the robustness of our findings. Results: In the developed group, a total of 879 patients were included. MVP was associated with OS and DFS defined by clinicopathological variables and remained an independent prognostic factor in the multivariate analysis (P = 0.001 and P = 0.002, respectively). For patients with high MVP, 5-year OS and 0DFS were significantly improved compared to those with low MPV (P = 0.0011 and P = 0.0018, respectively). Subgroup analysis revealed that POCRT was associated with improved 5-year OS and DFS compared with S alone in the low-MVP group (P < 0.0001 and P = 0.0002, respectively). External validation group analysis (n = 118) showed that POCRT significantly increased 5-year OS and DFS (P = 0.0035 and P = 0.0062, respectively) in patients with low MPV. For patients with high MPV, POCRT group showed similar survival rates compared with S alone in the developed and validation groups. Conclusions: MPV as a novel biomarker may serve as an independent prognosis factor and contribute to identifying patients most likely to benefit from POCRT for LA-ESCC.

Synthesis, radiolabeling, and evaluation of a (4-quinolinoyl)glycyl-2-cyanopyrrolidine analogue for fibroblast activation protein (FAP) PET imaging.

Fibroblast activation protein (FAP) is regarded as a promising target for the diagnosis and treatment of tumors as it was overexpressed in cancer-associated fibroblasts. FAP inhibitors bearing a quinoline scaffold have been proven to show high affinity against FAP in vitro and in vivo, and the scaffold has been radio-labeled for the imaging and treatment of FAP-positive tumors. However, currently available FAP imaging agents both contain chelator groups to enable radio-metal labeling, making those tracers more hydrophilic and not suitable for the imaging of lesions in the brain. Herein, we report the synthesis, radio-labeling, and evaluation of a 18F-labeled quinoline analogue ([18F]3) as a potential FAP-targeted PET tracer, which holds the potential to be blood-brain barrier-permeable. [18F]3 was obtained by one-step radio-synthesis via a copper-mediated SNAR reaction from a corresponding boronic ester precursor. [18F]3 showed moderate lipophilicity with a log D 7.4 value of 1.11. In cell experiments, [18F]3 showed selective accumulation in A549-FAP and U87 cell lines and can be effectively blocked by the pre-treatment of a cold reference standard. Biodistribution studies indicated that [18F]3 was mainly excreted by hepatic clearance and urinary excretion, and it may be due to its moderate lipophilicity. In vivo PET imaging studies indicated [18F]3 showed selective accumulation in FAP-positive tumors, and specific binding was confirmed by blocking studies. However, low brain uptake was observed in biodistribution and PET imaging studies. Although our preliminary data indicated that [18F]3 holds the potential to be developed as a blood-brain barrier penetrable FAP-targeted PET tracer, its low brain uptake limits its application in the detection of brain lesions. Herein, we report the synthesis and evaluation of [18F]3 as a novel small-molecule FAPI-targeted PET tracer, and our results suggest further structural optimizations would be needed to develop a BBB-permeable PET tracer with this scaffold.

Comparison of Al 18F-NOTA-FAPI-04 and 18F-FDG in recurrent esophageal cancer after surgery.

Recently, radionuclide labelling fibroblast activating protein inhibitors (FAPI) is regarded as the most promising imaging tracer forvarious tumours. Here we present the imaging finding of aluminium-[18F] fluoride (Al18F)-labelled 1,4,7-triazacyclononane-N,N',N"-triacetic acid (Al18F-NOTA-FAPI-04) and fluorine-18-fluorodeoxyglucose (18F-FDG) in postoperative recurrence esophageal cancer. The results presented that imaging with Al18F-NOTA-FAPI-04 showed significant improvement in detection of local recurrence and distant metastasis with higher maximum standardized uptake value (SUVmax) in the lesions compared with 18F-FDG.

The prognostic value of positron emission tomography/computed tomography-based parameters in locally advanced esophageal squamous cell carcinoma treated with chemoradiation therapy.

OBJECTIVES: To assess the prognostic value of PET/computed tomography-based parameters in patients with locally advanced esophageal squamous cell carcinoma (ESSC). METHODS: Sixty-seven patients with ESSC undergoing definitive chemoradiotherapy (dCRT) were retrospectively enrolled. PET/CT parameters (maximum standardized uptake value (SUVmax) metabolic tumor volume (MTV), and total glycolysis (TLG) were obtained from 18F-fluorodeoxyglucose (18F-FDG) PET/CT studies. The correlation between overall survival and PET/CT parameters was analyzed using a Cox proportional hazards model. RESULTS: There were no differences in TLG, MTV, and SUVmax values across age, sex, tumor location, and lymph node status. However, for patients with cT3-4 disease, TLG and SUVmax were significantly higher (P = 0.019 and P = 0.018, respectively), and MTV showed an increasing trend (P = 0.068). There were significant correlations among TLG, MTV and SUVmax. According to the receiver-operating curve, the cutoff values of TLG, MTV and SUVmax dichotomized by survival status at 2 years were 64.00 g, 9.63 ml and 9.97 g/ml, respectively. In univariate analysis, increased TLG, MTV and SUVmax were significant negative prognostic factors for OS. However, in multivariate analysis, only SUVmax was an independent prognostic factor for overall survival (hazard ratios = 2.857, 95% confidence intervals: 1.837-4.442; P = 0.017). CONCLUSIONS: PET/CT is a useful tool for predicting the prognoses in patients with locally advanced ESSC treated with dCRT. Future prospective studies with a large number of samples should be conducted to confirm these results.

Strategic Design of Amyloid-ß Species Fluorescent Probes for Alzheimer's Disease.

Alzheimer's disease (AD) is a high mortality and high disability rates neurodegenerative disease characterized by irreversible progression and poses a significant social and economic burden throughout the world. However, currently approved AD therapeutic agents only alleviate symptoms and there is still a lack of practical therapeutic regimens to stop or slow the progression of this disease. Thus, there is urgently needed novel diagnosis tools and drugs for early diagnosis and treatment of AD. Among several AD pathological hallmarks, amyloid-ß (Aß) peptide deposition is considered a critical initiating factor in AD. In recent years, with the advantages of excellent sensitivity and high resolution, near-infrared fluorescence (NIRF) imaging has attracted the attention of many researchers to develop Aß plaque probes. This review mainly focused on different NIRF probe design strategies for imaging Aß species to pave the way for the future design of novel NIRF probes for early diagnosis AD.

Prospective open-label non-inferiority randomised controlled trial comparing letrozole and mifepristone pretreatment in medical management of first trimester missed miscarriage: study protocol.

INTRODUCTION: Medical treatment is a less invasive alternative to surgical management of missed miscarriage. Studies have shown that pretreatment with mifepristone can increase the complete abortion rate in management of first-trimester missed miscarriage compared with misoprostol alone. Two studies have also shown that pretreatment with letrozole could increase the efficacy compared with misoprostol alone. So far, there is no trial comparing letrozole and mifepristone pretreatment for missed miscarriage. We designed this randomised controlled trial to test the hypothesis that for first-trimester missed miscarriage, letrozole pretreatment is non-inferior to mifepristone pretreatment followed by misoprostol in terms of complete abortion rate. METHODS AND ANALYSIS: This is a prospective open-label non-inferiority randomised controlled trial conducted in a single centre. In total, 294 women diagnosed with first-trimester missed miscarriage opting for medical treatment is recruited with informed consent. They are randomly assigned to receive mifepristone or letrozole pretreatment. In the mifepristone group, each woman takes 200 mg mifepristone orally followed 24-48 hours later by 800 µg misoprostol vaginally. In the letrozole group, each woman takes 10 mg letrozole orally per day for 3 days, followed by 800 µg misoprostol vaginally on the third day of letrozole administration. Follow-up is conducted on days 15 and 42 after misoprostol administration. The primary outcome is the overall complete abortion rate. Secondary outcomes include side effects and complications during the study period. Data will be analysed with both intention-to-treat and per protocol approaches. A p<0.05 will be considered as indicating statistical significance. ETHICS AND DISSEMINATION: Ethics approval has been obtained from the Institutional Review Board of the University of Hong Kong-Shenzhen Hospital with approval number: (2020)166. Findings will be disseminated in a peer-reviewed journal and in national and/or international meetings to guide future practice. TRIAL REGISTRATION NUMBER: ChiCTR2000041480.

The diagnostic accuracy of O-(2-18F-fluoroethyl)-L-tyrosine parameters for the differentiation of brain tumour progression from treatment-related changes.

BACKGROUND: 18F-fluoro-ethyl-tyrosine (18F-FET) is recommended to distinguish brain tumours post-therapeutic true progression (including recurrent and metastatic brain tumours) and treatment-related change (TRC). However, many parameters of 18F-FET can be used for this differential diagnosis. Our purpose was to investigate the diagnostic accuracy of various 18F-FET parameters to differentiate true progression from TRC. METHODS: We performed a literature search using the following databases: the PubMed, Embase and Web of Science databases up to 29 November 2020. We included studies that reported the diagnostic test results of 18F-FET to distinguish true progression from TRC. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to evaluate the quality of the included studies. The diagnostic accuracy of various parameters was pooled using a random-effects model. RESULTS: We included 17 eligible studies (nine parameters). For static parameters of 18F-FET, the maximum and mean tumour-to-brain ratios (TBRmax and TBRmean) showed similar pooled sensitivities of 82% [95% confidence interval (CI), 80-85%) and 82% (95% CI, 78-85%), respectively. Among the three kinetic parameters (slope, time to peak and kinetic pattern), the kinetic pattern presented the optimal diagnostic value with a pooled sensitivity of 81% (95% CI, 75-86%). When combining the static and kinetic parameters, the diagnostic performance of 18F-FET was significantly improved, with a pooled sensitivity of 90% (95% CI, 84-94%) in the combination of TBR and kinetic patterns. CONCLUSIONS: 18F-FET static parameters alone showed a comparably high sensitivity in the differentiation between brain tumour true progression and TRC. Combining static and kinetic parameters provided improved diagnostic performance.

Therapeutic efficacy of clomiphene citrate combined with metformin in patients with polycystic ovary syndrome.

WHAT IS KNOWN AND OBJECTIVE: Although several clinical trials have compared the clinical efficacy of clomiphene citrate (CC) combined with metformin (MET) in the treatment of women with polycystic ovary syndrome (PCOS), the results are controversial. Therefore, this study was designed to conduct a pooled analysis to evaluate the efficacy of CC combined with MET versus CC in these patients. METHODS: Computerized searches of the PubMed, Web of Science, Embase and Cochrane Library databases were conducted to identify eligible randomized controlled trials (RCTs) from the data obtained up to June 2021. The Cochrane Collaboration risk of bias tool was used to assess the risk of bias in individual RCTs, and RevMan 5.4 was used for data statistical analysis. RESULTS AND DISCUSSION: A total of 13 RCTs were included in the meta-analysis. These studies involved 1,353 patients, 707 of these were in the combination group and 646 in the monotherapy group. The results indicated a higher clinical pregnancy rate (risk ratio [RR] 1.28, 95% confidence interval [CI] 1.06-1.54, p = 0.01) in the combined group compared to the monotherapy group. However, no significant differences were observed in the ovulation rate (RR 1.13, 95% CI 0.98-1.30, p = 0.10), live birth rate (RR 1.13, 95% CI 0.89-1.42, p = 0.32), multiple pregnancy rate (RR 0.58, 95% CI 0.19-1.73, p = 0.33) and abortion rate (RR 1.26, 95% CI 0.86-1.84, p = 0.23) between the two groups. WHAT IS NEW AND CONCLUSION: CC combined with MET has an advantage in improving the clinical pregnancy rate compared to CC alone; however, there is no significant difference in the rate of ovulation. For better management of PCOS, a high-quality RCT is needed to demonstrate the safety of the combination.

Clinical Characteristics and Prognosis of HER2 Gene Phenotype in Patients with Non-Small Cell Lung Cancer.

INTRODUCTION: We aim to investigate the relationship between HER2 gene phenotype and clinical characteristics, distribution and prognosis of non-small cell lung cancer (NSCLC) patients. METHODS: A total of 249 NSCLC patients admitted to the oncology department of our hospital from January 2015 to January 2018 were retrospectively analyzed. The clinicopathological information, CT signs, clinical efficacy and long-term prognosis were collected and compared. RESULTS: A total of 249 NSCLC patients underwent HER2 gene testing, 21 of them (8.43%) complied with HER2 alterations [HER2 (+)], and there were significant differences in tumor stages among patients with different HER2 phenotypes (P<0.05). Among 21 NSCLC patients with HER2 (+), HER2 gene mutation was found in 17 patients (81%), and HER2 gene amplification in 4 patients (19%). Among the HER2 mutations, 12 cases (57%) were 20 exon mutations, and 5 cases (19%) were other mutations. Analysis of CT signs showed that border lobulation/burr, necrosis sign and pleural depression were correlated with HER2 gene mutation (P<0.05). The incidence of EGRF mutation in HER (+) patients was significantly lower than that in HER (-) patients (P<0.05), but there was no significant difference in the incidence of ALK gene mutation among different HER phenotypes (P>0.05). The disease control rate of HER2 (+) patients was significantly lower than that of HER2 (-) patients, and the 12-month progression-free survival rate and survival rate of HER2 (+) patients were significantly higher than those of HER2 (-) patients (P<0.05). There was no significant difference in the incidence of ADR among HER2 patients with different phenotypes, but the incidence of ADR (adverse drug reaction) in HER2 (+) patients with Grade 3 or 4 was significantly higher than that in the control group (P<0.05). DISCUSSION: The incidence of HER2 gene mutations in NSCLC patients is relatively low, but it is far commoner in patients with stage IIIB~IV, among which exon 20 mutations are the most prevalent. In CT signs, the lesion lobulated sign/spiculated sign, necrosis signs, and pleural depression signs are related to HER2 gene mutations. In addition, HER2 gene mutations play a crucial role in the clinical prognosis and treatment safety of patients.

Radiomics in Differentiated Thyroid Cancer and Nodules: Explorations, Application, and Limitations.

Radiomics is an emerging technique that allows the quantitative extraction of high-throughput features from single or multiple medical images, which cannot be observed directly with the naked eye, and then applies to machine learning approaches to construct classification or prediction models. This method makes it possible to evaluate tumor status and to differentiate malignant from benign tumors or nodules in a more objective manner. To date, the classification and prediction value of radiomics in DTC patients have been inconsistent. Herein, we summarize the available literature on the classification and prediction performance of radiomics-based DTC in various imaging techniques. More specifically, we reviewed the recent literature to discuss the capacity of radiomics to predict lymph node (LN) metastasis, distant metastasis, tumor extrathyroidal extension, disease-free survival, and B-Raf proto-oncogene serine/threonine kinase (BRAF) mutation and differentiate malignant from benign nodules. This review discusses the application and limitations of the radiomics process, and explores its ability to improve clinical decision-making with the hope of emphasizing its utility for DTC patients.

Altered intrinsic brain activity in patients with hepatic encephalopathy.

Neuropsychiatric deficits are common in patients with liver cirrhosis (LC), especially in those with hepatic encephalopathy (HE). Previous studies reveal abnormalities in brain activity underlying the neuropsychiatric deficits in LC patients; however, the results are inconsistent. We conducted a meta-analysis of resting-state functional magnetic resonance imaging studies using anisotropic effect-size signed differential mapping software on LC patients to characterize the most consistent regional activity alterations, and to evaluate the potential effect of liver transplantation (LT) on brain function. Meta-regression analyses were performed to explore the relationship between brain alterations and clinical variables. Compared with healthy controls, the typical patterns of increased regional activity in the fronto-striato-cerebellar network and decreased activity in the visuo-sensorimotor network and cingulate gyrus were identified in LC patients, which remained significant in the subgroup meta-analyses of minimal HE (MHE) and overt HE (OHE) patients. Functional deficits in the default mode network (DMN) were found in OHE patients compared with MHE patients. Ammonia level positively correlated with brain activity in the right middle temporal gyrus, and the completion time of number connection test A negatively correlated with brain activity in the left anterior cingulate gyrus. In addition, patients showed increased activity in the visuo-sensorimotor network and precuneus after LT. Our study suggests that alterations in the fronto-striato-cerebellar and visuo-sensorimotor networks may be the potential pathophysiological mechanisms underlying HE, and deficits in the DMN may indicate the progression of HE. LT may improve brain function in the visuo-sensorimotor network. This study has registered in the PROSPERO (CRD42020212758).

Gray Matter Atrophy in the Cortico-Striatal-Thalamic Network and Sensorimotor Network in Relapsing-Remitting and Primary Progressive Multiple Sclerosis.

Gray matter atrophy in multiple sclerosis (MS) is thought to be associated with disability and cognitive impairment, but previous studies have sometimes had discordant results, and the atrophy patterns of relapsing-remitting multiple sclerosis (RRMS) and primary progressive multiple sclerosis (PPMS) remain to be clarified. We conducted a meta-analysis using anisotropic effect-size-based algorithms (AES-SDM) to identify consistent findings from whole-brain voxel-based morphometry (VBM) studies of gray matter volume (GMV) in 924 RRMS patients and 204 PPMS patients. This study is registered with PROSPERO (number CRD42019121319). Compared with healthy controls, RRMS and PPMS patients showed gray matter atrophy in the cortico-striatal-thalamic network, sensorimotor network, and bilateral insula. RRMS patients had a larger GMV in the left insula, cerebellum, right precentral gyrus, and bilateral putamen as well as a smaller GMV in the bilateral cingulate, caudate nucleus, right thalamus, superior temporal gyrus and left postcentral gyrus than PPMS patients. The disease duration, Expanded Disability Status Scale score, Paced Auditory Serial Addition Test z-score, and T2-weighted lesion load were associated with specific gray matter regions in RRMS or PPMS. Alterations in the cortico-striatal-thalamic networks, sensorimotor network, and insula may be involved in the common pathogenesis of RRMS and PPMS. The deficits in the cingulate gyrus and caudate nucleus are more apparent in RRMS than in PPMS. The more severe cerebellum atrophy in PPMS may be a brain feature associated with its neurological manifestations. These imaging biomarkers provide morphological evidence for the pathophysiology of MS and should be verified in future research.

Age-related changes of standardized uptake values in the blood pool and liver: a decade-long retrospective study of the outcomes of 2,526 subjects.

BACKGROUND: Background activity on fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) is often used as a reference to assess a patient's response to tumor treatment. To produce a suitable background activity reference, we examined the variations in standardized uptake values (SUVs) in the blood pool and liver of a large multi-aged population. METHODS: A total of 2,526 subjects underwent 18F-FDG PET/CT examinations and were divided into 12 age groups. Pearson's partial correlation and multivariate regression analyses were performed to assess the associations between individual factors and SUVs of the blood pool and liver and to identify the factor that most influenced the SUVs. The mean SUVs across the age groups were also determined. RESULTS: Positive correlations were found between individual factors and SUVs. Age appeared to be the most important predictor of SUVs and was significantly associated with the blood pool SUVmax (ß=0.466, P=0.000), blood pool SUVmean (ß=0.393, P=0.000), liver SUVmax (ß=0.347, P=0.000), and liver SUVmean (ß=0.354, P=0.000). Blood pool and liver SUVs rose rapidly until the age of 20 and then showed a slow upward trend without reaching a plateau. CONCLUSIONS: Age is an important factor that influences variations in the blood pool and liver SUVs. Our study clarified this understanding of age-related variations in SUVs and provided a normal range of blood pool and liver SUVs that may aid clinicians in evaluating tumors with greater accuracy.

Three-dimensional simulation of reservoir temperature and pollutant transport by the lattice Boltzmann method.

Predicting the three-dimensional (3D) transport processes of reservoir temperature and pollutants is essential for water environmental protection and restoration, and introducing the lattice Boltzmann (LB) method into this prediction is necessary because of its simple algorithm, straightforward implementation of boundary conditions, and high computation efficiency. In this paper, a triple-distribution function (TDF) LB model for flow-temperature-concentration coupling simulations is introduced. Some essential techniques for implementing this method in 3D reservoirs are also described, including the treatment of water surface fluctuation, the consideration of surface heat exchange, and the hardware acceleration using the graphics processing unit (GPU). Two cases verified the proposed model, and then, the temporal-spatial variations of flow, temperature, and pollutants in the upper reservoir of a pumped-storage power station during both pumping and generating modes were analyzed to demonstrate its applicability. In the reservoir, the water forms several circulations, the cold water from the inlet flows as an undercurrent firstly, and then spread laterally, and the spreading of pollutants directly relates to the flow velocity. The results of flow, temperature, and concentration fields in different working conditions are consistent with model tests and physical laws, which shows good prospects of the proposed LB model.