A radiomics signature derived from CT imaging to predict MSI status and immunotherapy outcomes in gastric cancer: a multi-cohort study.

BACKGROUND: Accurate microsatellite instability (MSI) testing is essential for identifying gastric cancer (GC) patients eligible for immunotherapy. We aimed to develop and validate a CT-based radiomics signature to predict MSI and immunotherapy outcomes in GC. METHODS: This retrospective multicohort study included a total of 457 GC patients from two independent medical centers in China and The Cancer Imaging Archive (TCIA) databases. The primary cohort (n = 201, center 1, 2017-2022), was used for signature development via Least Absolute Shrinkage and Selection Operator (LASSO) and logistic regression analysis. Two independent immunotherapy cohorts, one from center 1 (n = 184, 2018-2021) and another from center 2 (n = 43, 2020-2021), were utilized to assess the signature's association with immunotherapy response and survival. Diagnostic efficiency was evaluated using the area under the receiver operating characteristic curve (AUC), and survival outcomes were analyzed via the Kaplan-Meier method. The TCIA cohort (n = 29) was included to evaluate the immune infiltration landscape of the radiomics signature subgroups using both CT images and mRNA sequencing data. RESULTS: Nine radiomics features were identified for signature development, exhibiting excellent discriminative performance in both the training (AUC: 0.851, 95%CI: 0.782, 0.919) and validation cohorts (AUC: 0.816, 95%CI: 0.706, 0.926). The radscore, calculated using the signature, demonstrated strong predictive abilities for objective response in immunotherapy cohorts (AUC: 0.734, 95%CI: 0.662, 0.806; AUC: 0.724, 95%CI: 0.572, 0.877). Additionally, the radscore showed a significant association with PFS and OS, with GC patients with a low radscore experiencing a significant survival benefit from immunotherapy. Immune infiltration analysis revealed significantly higher levels of CD8 + T cells, activated CD4 + B cells, and TNFRSF18 expression in the low radscore group, while the high radscore group exhibited higher levels of T cells regulatory and HHLA2 expression. CONCLUSION: This study developed a robust radiomics signature with the potential to serve as a non-invasive biomarker for GC's MSI status and immunotherapy response, demonstrating notable links to post-immunotherapy PFS and OS. Additionally, distinct immune profiles were observed between low and high radscore groups, highlighting their potential clinical implications.

[Photochemical Mechanism and Control Strategy Optimization for Summertime Ozone Pollution in Yining City].

To explore the formation mechanism of the ozone （O3） and emission reduction strategy in a northwestern city， an extensive field campaign was conducted in summertime in 2021 in Yining City， in which the 0-D box model incorporating the latest explicit chemical mechanism （MCMv3.3.1） was applied for the first time to quantify the O3-NOx-VOCs sensitivity and formulate a precise O3 control strategy in this city. The results showed that： ① the three indicators ï¼»i.e.， O3 formation potential （OFP）， ·OH reaction rate （k·OH）， and relative incremental reactivity （RIR）］ jointly indicated that alkenes， oxygenated volatile organic compounds （OVOCs）， and aromatics were the highest contributors among anthropogenic volatile organic compounds （AVOC） to O3 formation， and the contribution of biogenic volatile organic compounds （BVOC） also could not be ignored. Additionally， the results based on RIR calculation implied that that the acetaldehyde， ethylene， and propylene were the most sensitive individual VOCs species in Yining City. ② The in-situ photochemical O3 variations were primarily influenced by the local photochemical production and export process horizontally to downwind areas or vertically to the upper layer， and the reaction pathways of HO2·+ NO and ·OH + NO2 contributed the most to the gross Ox photochemical production （60%） and photochemical destruction production （53%）， respectively. Hence， the reduction in local emissions for O3 precursors was more essential to alleviate O3 pollution in this city. ③ The outcome based on RIR（NOx） / RIR（AVOC） and EKMA jointly suggested that the photochemical regime in this city can be considered a transitional regime that was also nearly a VOCs-limited regime. Detailed mechanism modeling based on multiple scenarios further suggested that the NOx and VOCs synergic emission reduction strategies was helpful to alleviate O3 pollution. These results are useful to provide policy-related guidance for other cities facing similar O3 pollution in northwest China.

Sepsis one-hour bundle management combined with psychological intervention on negative emotion and sleep quality in patients with sepsis.

BACKGROUND: Sepsis is a serious infectious disease caused by various systemic inflammatory responses and is ultimately life-threatening. Patients usually experience depression and anxiety, which affect their sleep quality and post-traumatic growth levels. AIM: To investigate the effects of sepsis, a one-hour bundle (H1B) management was combined with psychological intervention in patients with sepsis. METHODS: This retrospective analysis included 300 patients with sepsis who were admitted to Henan Provincial People's Hospital between June 2022 and June 2023. According to different intervention methods, the participants were divided into a simple group (SG, n = 150) and combined group (CG, n = 150). H1B management was used in the SG and H1B management combined with psychological intervention was used in the CG. The changes of negative emotion, sleep quality and post-traumatic growth and prognosis were compared between the two groups before (T0) and after (T1) intervention. RESULTS: After intervention (T1), the scores of the Hamilton Anxiety scale and Hamilton Depression scale in the CG were significantly lower than those in the SG (P < 0.001). Sleep time, sleep quality, sleep efficiency, daytime dysfunction, sleep disturbance dimension score, and the total score in the CG were significantly lower than those in the SG (P < 0.001). The appreciation of life, mental changes, relationship with others, personal strength dimension score, and total score of the CG were significantly higher than those of the SG (P < 0.001). The scores for mental health, general health status, physiological function, emotional function, physical pain, social function, energy, and physiological function in the CG were significantly higher than those in the SG (P < 0.001). The mechanical ventilation time, intensive care unit stay time, and 28-d mortality of the CG were significantly lower than those of the SG (P < 0.05). CONCLUSION: H1B management combined with psychological intervention can effectively alleviate the negative emotions of patients with sepsis and increase their quality of sleep and life.

Can visceral fat parameters based on computed tomography be used to predict occult peritoneal metastasis in gastric cancer?

BACKGROUND: The preoperative prediction of peritoneal metastasis (PM) in gastric cancer would prevent unnecessary surgery and promptly indicate an appropriate treatment plan. AIM: To explore the predictive value of visceral fat (VF) parameters obtained from preoperative computed tomography (CT) images for occult PM and to develop an individualized model for predicting occult PM in patients with gastric carcinoma (GC). METHODS: A total of 128 confirmed GC cases (84 male and 44 female patients) that underwent CT scans were analyzed and categorized into PM-positive (n = 43) and PM-negative (n = 85) groups. The clinical characteristics and VF parameters of two regions of interest (ROIs) were collected. Univariate and stratified analyses based on VF volume were performed to screen for predictive characteristics for occult PM. Prediction models with and without VF parameters were established by multivariable logistic regression analysis. RESULTS: The mean attenuations of VFROI 1 and VFROI 2 varied significantly between the PM-positive and PM-negative groups (P = 0.044 and 0.001, respectively). The areas under the receiver operating characteristic curves (AUCs) of VFROI 1 and VFROI 2 were 0.599 and 0.657, respectively. The mean attenuation of VFROI 2 was included in the final prediction combined model, but not an independent risk factor of PM (P = 0.068). No significant difference was observed between the models with and without mean attenuation of VF (AUC: 0.749 vs 0.730, P = 0.339). CONCLUSION: The mean attenuation of VF is a potential auxiliary parameter for predicting occult PM in patients with GC.

[Photochemical Mechanism and Control Strategy Optimization for Summertime Ozone Pollution in an Industrial City in the North China Plain].

To investigate the characteristics and formation mechanism of ozone (O3) pollution in an industrial city, an extensive one-month field campaign focusing on O3 and its precursors (e.g., volatile organic compounds[VOC] and nitrogen oxides[NOx]) was conducted in Zibo City, a highly industrializd city in the North China Plain, in June 2021. The 0-D box model incorporating the latest explicit chemical mechanism (MCMv3.3.1) was applied using an observation dataset (e.g., VOC, NOx, HONO, and PAN) as model contraints to explore the optimal reduction strategy for O3 and its precursors. The results showed that ① during high-O3 episodes, stagnant weather conditions with high temperature and solar radiation as well as low relative humidity were observed, and oxygenated VOCs and alkenes from anthropogenic VOCs contributed the most to the total ozone formation potential and OH reactivity (k·OH). ② The in-situ O3 variation was primarily affected by local photochemical production and export process horizontal to downwind areas or vertical to the upper layer. The reduction in local emissions was essential to alleviate O3 pollution in this region. ③ During high-O3 episodes, high concentrations of ·OH (10×106 cm-3) and HO2· (14×108 cm-3) radical drove and generated a high O3 production rate (daytime peak value reached 36×10-9 h-1). The reaction pathways of HO2·+NO and ·OH+NO2 contributed the most to the in-situ gross Ox photochemical production (63%) and photochemical destruction (50%), respectively. ④ Compared to those during low-O3 episodes, the photochemical regimes during high-O3 episodes were more inclined to be considered as the NOx-limited regime. Detailed mechanism modeling based on multiple scenarios further suggested that the synergic emission reduction strategy of NOx and VOC, while focusing on NOx emission alleviation, would be practical options for controlling local O3 pollutions. This method could also provide policy-related guidance for the precise O3 pollution prevention and control in other industrialized Chinese cities.

Intravascular papillary endothelial hyperplasia of the spleen in a child: a case report.

BACKGROUND: Intravascular papillary endothelial hyperplasia (IPEH) is a vascular tumor characterized by the proliferation of endothelial cells with papillary formation. It is a rare benign condition affecting the head and neck. Currently, no cases of IPEH of the spleen have been reported. Here, we report a case of IPEH of the spleen in a child and discuss its clinical manifestations, imaging features, and surgical treatment. CASE PRESENTATION: A 5-year-old female presented with a 4-month-old tumor in the left upper abdomen, abdominal pain, and constipation. She underwent radiography, barium enema, US, and MRI. A solid space-occupying mass was found in the left abdominal cavity on preoperative imaging, and it was diagnosed as angiosarcoma. The lesion was surgically resected. Histopathological analysis was consistent with IPEH. CONCLUSION: Clinicians should consider the possibility of IPEH in patients presenting with tumors in the spleen, which is curable by surgical resection. Malignant vascular tumors must be excluded in the differential diagnosis of IPEH to prevent misdiagnosis and inappropriate overtreatment.

Use of radiomics containing an effective peritumoral area to predict early recurrence of solitary hepatocellular carcinoma ≤5 cm in diameter.

Background: Hepatocellular carcinoma (HCC) is the sixth leading type of cancer worldwide. We aimed to develop a preoperative predictive model of the risk of early tumor recurrence after HCC treatment based on radiomic features of the peritumoral region and evaluate the performance of this model against postoperative pathology. Method: Our model was developed using a retrospective analysis of imaging and clinicopathological data of 175 patients with an isolated HCC ≤5 cm in diameter; 117 patients were used for model training and 58 for model validation. The peritumoral area was delineated layer-by-layer for the arterial and portal vein phase on preoperative dynamic enhanced computed tomography images. The volume area of interest was expanded by 5 and 10 mm and the radiomic features of these areas extracted. Lasso was used to select the most stable features. Results: The radiomic features of the 5-mm area were sufficient for prediction of early tumor recurrence, with an area under the curve (AUC) value of 0.706 for the validation set and 0.837 for the training set using combined images. The AUC of the model using clinicopathological information alone was 0.753 compared with 0.786 for the preoperative radiomics model (P >0.05). Conclusions: Radiomic features of a 5-mm peritumoral region may provide a non-invasive biomarker for the preoperative prediction of the risk of early tumor recurrence for patients with a solitary HCC ≤5 cm in diameter. A fusion model that combines the radiomic features of the peritumoral region and postoperative pathology could contribute to individualized treatment of HCC.

Application of computed tomography-based radiomics in differential diagnosis of adenocarcinoma and squamous cell carcinoma at the esophagogastric junction.

BACKGROUND: The biological behavior of carcinoma of the esophagogastric junction (CEGJ) is different from that of gastric or esophageal cancer. Differentiating squamous cell carcinoma of the esophagogastric junction (SCCEG) from adenocarcinoma of the esophagogastric junction (AEG) can indicate Siewert stage and whether the surgical route for patients with CEGJ is transthoracic or transabdominal, as well as aid in determining the extent of lymph node dissection. With the development of neoadjuvant therapy, preoperative determination of pathological type can help in the selection of neoadjuvant radiotherapy and chemotherapy regimens. AIM: To establish and evaluate computed tomography (CT)-based multiscale and multiphase radiomics models to distinguish SCCEG and AEG preoperatively. METHODS: We retrospectively analyzed the preoperative contrasted-enhanced CT imaging data of single-center patients with pathologically confirmed SCCEG (n = 130) and AEG (n = 130). The data were divided into either a training (n = 182) or a test group (n = 78) at a ratio of 7:3. A total of 1409 radiomics features were separately extracted from two dimensional (2D) or three dimensional (3D) regions of interest in arterial and venous phases. Intra-/inter-observer consistency analysis, correlation analysis, univariate analysis, least absolute shrinkage and selection operator regression, and backward stepwise logical regression were applied for feature selection. Totally, six logistic regression models were established based on 2D and 3D multi-phase features. The receiver operating characteristic curve analysis, the continuous net reclassification improvement (NRI), and the integrated discrimination improvement (IDI) were used for assessing model discrimination performance. Calibration and decision curves were used to assess the calibration and clinical usefulness of the model, respectively. RESULTS: The 2D-venous model (5 features, AUC: 0.849) performed better than 2D-arterial (5 features, AUC: 0.808). The 2D-arterial-venous combined model could further enhance the performance (AUC: 0.869). The 3D-venous model (7 features, AUC: 0.877) performed better than 3D-arterial (10 features, AUC: 0.876). And the 3D-arterial-venous combined model (AUC: 0.904) outperformed other single-phase-based models. The venous model showed a positive improvement compared with the arterial model (NRI > 0, IDI > 0), and the 3D-venous and combined models showed a significant positive improvement compared with the 2D-venous and combined models (P < 0.05). Decision curve analysis showed that combined 3D-arterial-venous model and 3D-venous model had a higher net clinical benefit within the same threshold probability range in the test group. CONCLUSION: The combined arterial-venous CT radiomics model based on 3D segmentation can improve the performance in differentiating EGJ squamous cell carcinoma from adenocarcinoma.

Postoperative multiple metastasis of clear cell sarcoma-like tumor of the gastrointestinal tract in adolescent: A case report.

BACKGROUND: Clear cell sarcoma-like tumor of the gastrointestinal tract (CCSLGT) is a rare malignant gastrointestinal mesenchymal soft tissue tumor. Its genetic feature is EWSR1 gene rearrangement. Histologically, it is often accompanied by a varying number of CD68-positive osteoclast-like giant cells. CCSLGT mostly occurs in the small intestinal wall of young people and children. In terms of clinical manifestations, there is no significant difference between it and other gastrointestinal tumors, and the diagnosis depends on immunohistochemistry and gene detection. CASE SUMMARY: A 16-year-old man developed dizziness and fatigue 2 mo ago, and 10 d ago showed progressive exacerbation of paroxysmal epigastric pain and stopped flatulence and defecation. Computed tomography showed a soft tissue mass in the distal ileum. After complete resection of the lesion, it was diagnosed by combined immunohistochemical and genetic examination as CCSLGT. After surgery, the patient gradually developed lymph node, liver, lung, bone, left thigh, pleura and adrenal metastasis. The survival time was 4 years and 8 mo. CONCLUSION: Whole abdominal computed tomography enhancement is recommended for patients with gastrointestinal symptoms. There is no effective treatment for CCSLGT with multiple metastases via the lymphatic system and bloodstream after surgical resection.

[Characteristics and Reactivity of VOCs in a Typical Industrial City in Summer].

To investigate the ambient pollution caused by volatile organic compounds (VOCs) in a typical industrial city in summer, the characteristics and chemical reactivity from VOCs and the causes of ozone (O3) pollution were analyzed using online VOCs measurements during polluted and non-polluted periods in Zibo city in July 2020. The results showed that the average hourly concentration of total volatile organic compounds (TVOC) during the polluted period[(50.6±28.3)] µg·m-3 was 32.5% higher than that during the non-polluted period[(38.2±24.9) µg·m-3]. The contribution of all VOCs categories were as follows:alkanes>aromatics>alkenes>alkynes, and the diurnal averages of TVOC and O3 concentrations were opposite during the polluted and non-polluted period. Ozone formation potential (OFP),·OH radical loss rate (L·OH), and secondary organic aerosol formation potential (SOAp) during the polluted period were higher than those during the non-polluted period. Alkenes contributed most to OFP and L·OH, whereas aromatics contributed most to SOAp. The tendency of the diurnal average of OFP and SOAp was overall consistent with that of TVOC. The priority species of OFP, L·OH, and SOAp were alkenes and aromatics. The VOCs/NOx method was applied to identify the O3-VOC-NOx sensitivity during the polluted and non-polluted periods, and the results showed that the photochemical regimes were VOCs-limited and transition regions. In addition, the smog production model (SPM) was employed to identify the O3 formation regime, and the results showed that those during the polluted period were identified as VOCs-limited and transition regions from 08:00 to 16:00, whereas the non-polluted period was mainly considered to be VOCs-limited. To mitigate the O3 pollution in summertime, the synergistic control of VOCs (especially alkenes and aromatics) and NOx emissions should be enforced.

The mediating effects of adversity quotient and self-efficacy on ICU nurses' organizational climate and work engagement.

AIM: This study aimed to explore the mediating effects of adversity quotient and the moderating effect of self-efficacy on the relationship between the organizational climate and the work engagement of intensive care unit nurses. BACKGROUND: A good organizational climate can contribute to a high level of work engagement. Adversity quotient and self-efficacy are the key factors affecting nurses' work engagement, while the mechanism of these factors in the organizational climate and work engagement remains unclear. This study was conducted to contribute to the relevant field research. METHODS: The study used a cross-sectional research design and surveyed 323 intensive care unit nurses working in a public hospital in China. The data were analysed using descriptive statistical methods: Pearson correlation analysis and PROCESS macro Model 7 in the regression analysis. RESULTS: Organizational climate was positively correlated with work engagement and adversity quotient. The indirect effect of organizational climate on work engagement through adversity quotient was positive. Furthermore, self-efficacy moderated the relationship between the two factors. CONCLUSION: Cultivating organizational climate and adversity quotients is an important strategy to improve the work engagement of intensive care unit nurses, particularly for nurses with high self-efficacy. IMPLICATIONS FOR NURSING MANAGEMENT: Administrators should make efforts to create a good organizational climate and cultivate nurses' adversity quotients and self-efficacy to decrease their intent to leave.

Age, gender, geographic and clinical differences for gallstones in China: a nationwide study.

Background: The etiology of gallstones at different anatomical locations may be varied. However, it has not been well studied about the prevalence of gallstones by anatomical locations and their associated factors in China. Methods: We used the data set from preventive health screening centers covering all provinces in mainland China except for Tibet, and a total of 10,937,993 adults were included, who received abdominal ultrasonography in 2017. We analyzed the prevalence of gallstones classified by anatomical locations, including gallbladder (GB) stones, intrahepatic bile duct (IHD) stones, and extrahepatic bile duct (EHD) stones. Further, their associated factors were investigated using a logistic regression model with body mass index (BMI), fasting glucose, total triglyceride, and previous cholecystectomy, with covariates of age and sex. Results: The age- and gender-standardized prevalence (AGS-prevalence) of gallstone diseases was 5.13% (95% CI: 5.11-5.14%). GB, IHD, and EHD stones accounted for 76.3%, 24.3%, and 0.2% of all gallstone cases (concomitant cases were present). GB, IHD, and EHD gallstones presented different patterns by the age, gender, geographic and metabolic factors. Overall, the age-standardized prevalence was higher in women than that in men (5.41% vs. 4.85%, P<0.001). The gender standardized prevalence of all gallstone subtypes apparently increased with age (P<0.001), especially for GB stones from 1.05% (age 18-30) to 11.6% (age ≥70) (P<0.001). There was a marked geographic variation with AGS-prevalence ranging from 3.00% to 8.86% among different provinces. Noticeably, higher BMI, fasting glucose level, or total triglyceride level was associated with a higher prevalence of overall gallstones and GB stones (OR >1), but associated with a lower prevalence of IHD and EHD stones. Conclusions: The prevalence of gallstones in China largely varied in its anatomical location, demographic factors, geographic location, and metabolic factors, suggesting that the etiology of each subtype may be different. Further investigation should be conducted.

Sero-prevalence of 19 infectious pathogens and associated factors among middle-aged and elderly Chinese adults: a cross-sectional study.

OBJECTIVES: To systematically assess the sero-prevalence and associated factors of major infectious pathogens in China, where there are high incidence rates of certain infection-related cancers. DESIGN: Cross-sectional study. SETTING: 10 (5 urban, 5 rural) geographically diverse areas in China. PARTICIPANTS: A subcohort of 2000 participants from the China Kadoorie Biobank. PRIMARY MEASURES: Sero-prevalence of 19 pathogens using a custom-designed multiplex serology panel and associated factors. RESULTS: Of the 19 pathogens investigated, the mean number of sero-positive pathogens was 9.4 (SD 1.7), with 24.4% of participants being sero-positive for >10 pathogens. For individual pathogens, the sero-prevalence varied, being for example, 0.05% for HIV, 6.4% for human papillomavirus (HPV)-16, 53.5% for Helicobacter pylori (H. pylori) and 99.8% for Epstein-Barr virus . The sero-prevalence of human herpesviruses (HHV)-6, HHV-7 and HPV-16 was higher in women than men. Several pathogens showed a decreasing trend in sero-prevalence by birth cohort, including hepatitis B virus (HBV) (51.6% vs 38.7% in those born <1940 vs >1970), HPV-16 (11.4% vs 5.4%), HHV-2 (15.1% vs 8.1%), Chlamydia trachomatis (65.6% vs 28.8%) and Toxoplasma gondii (22.0% vs 9.0%). Across the 10 study areas, sero-prevalence varied twofold to fourfold for HBV (22.5% to 60.7%), HPV-16 (3.4% to 10.9%), H. pylori (16.2% to 71.1%) and C. trachomatis (32.5% to 66.5%). Participants with chronic liver diseases had >7-fold higher sero-positivity for HBV (OR=7.51; 95% CI 2.55 to 22.13). CONCLUSIONS: Among Chinese adults, previous and current infections with certain pathogens were common and varied by area, sex and birth cohort. These infections may contribute to the burden of certain cancers and other non-communicable chronic diseases.

Pleomorphic adenoma of the left lacrimal gland recurred and transformed into myoepithelial carcinoma after multiple operations: A case report.

BACKGROUND: Myoepithelial carcinoma (MC) is a clinically rare malignancy, there is controversy regarding its etiology and its biological behavior is not fully elucidated. Extensive surgical resection is the main treatment method. We describe a case of pleomorphic adenoma (PA) with multiple postoperative recurrences after malignant transformation, and the history of the disease in this patient was more than 20 years. Complete resection during the first surgery of PA and long-term postoperative follow-up is necessary. CASE SUMMARY: A 34-year-old male with PA and a history of 5 postoperative recurrences over 21 years, each surgically removed, presented 15 d ago with headache, nasal congestion, protrusion of the right eyeball and loss of vision in the right eye, with progressively worsening symptoms. The patient underwent surgery, and MC was confirmed by pathology examination. A small PA component was locally visible under light microscope. The patient had a recurrence of the tumor 2 mo after surgery and underwent surgical resection. CONCLUSION: During the first operation for PA, care should be taken not to rupture the envelope to prevent tumor cell implantation, and when complete resection is not possible due to the anatomical site, postoperative radiotherapy is necessary to control the lesion and prevent infiltration and malignant transformation of the tumor to MC. Computed tomography and magnetic resonance imaging is important for establishing diagnosis and developing a treatment plan.

[Comparison of VOCs Pollution Characteristics Between an Urban Site and a Background Site in Summer in Zibo].

To study the differences in volatile organic compound (VOCs) pollution characteristics between an urban site and a background site in summer, ambient VOCs were monitored using an online gas chromatograph (GC) at an urban site and a background site (Mt. Lu) in Zibo in July 2020. The VOCs pollution characteristics and chemical reactivity were analyzed, and the sources of VOCs were identified using the positive matrix factorization model(PMF). The results showed that ρ(TVOC) and ρ(NOx) were higher at the urban site, but ρ(O3) was higher at the background site. Diurnal average characteristics of ρ(TVOC) and ρ(NOx) were high at night and low during the day at the urban site, and there were no obvious variation characteristics at the background site. The diurnal average characteristics of ρ(O3) were consistent at the urban and background sites, showing low level at night and high level during the day; however, the peak in the background site was later than that at the urban site. The average ρ(TVOC) at the urban site and background site were (44.9±27.5) µg·m-3 and (17.3±9.1) µg·m-3, respectively, and the mass fraction of each component was ordered as alkanes>aromatics>alkenes>alkynes in both sites. The average ozone formation potentials(OFP)were (115.5±63.1) µg·m-3 and (38.0±20.2) µg·m-3, and the contribution of each component was ordered as alkenes>aromatics>alkanes>alkynes. The respective average values of·OH radical loss rate(L·OH) were (3.9±2.3) s-1 and (1.0±0.6) s-1, with the highest contribution of alkenes and the lowest contribution of alkynes in both sites. The average values of secondary organic aerosol formation potential(SOAp) were (0.5±0.3) µg·m-3 and (0.2±0.06) µg·m-3, respectively, with aromatic being the most abundant group. According to the source appointment by the PMF model, the main source of VOCs in the urban site was traffic sources (52.4%), followed by petroleum evaporation (19.2%), solvent evaporation (17.3%), and oil and biological sources (11.1%). The source of VOCs in the background site mainly came from traffic sources (40.2%), followed by solvent evaporation (31.3%), combustion sources (19.3%), and biological sources (9.2%). Zibo City should strengthen the management and control of motor vehicle emissions, petroleum evaporation, and the use of industrial solvents.

Symptomatic and Asymptomatic SARS-CoV-2 Infection and Follow-up of Neutralizing Antibody Levels.

Objective: To investigate neutralizing antibody levels in symptomatic and asymptomatic patients with coronavirus disease 2019 (COVID-19) at 6 and 10 months after disease onset. Methods: Blood samples were collected at three different time points from 27 asymptomatic individuals and 69 symptomatic patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Virus-neutralizing antibody titers against SARS-CoV-2 in both groups were measured and statistically analyzed. Results: The symptomatic and asymptomatic groups had higher neutralizing antibodies at 3 months and 1-2 months post polymerase chain reaction confirmation, respectively. However, neutralizing antibodies in both groups dropped significantly to lower levels at 6 months post-PCR confirmation. Conclusion: Continued monitoring of symptomatic and asymptomatic individuals with COVID-19 is key to controlling the infection.

Computed Tomography Features and Clinical Prognostic Characteristics of Hepatoid Adenocarcinoma of the Stomach.

PURPOSE: Hepatoid adenocarcinoma of the stomach (HAS) is a highly malignant and aggressive tumor. The purpose of this study was to describe the clinical, computed tomography (CT), and prognostic features of HAS to increase the awareness of this entity and determine its distinguishing features from non-HAS tumors. METHODS: The CT features and clinical data of 47 patients in our hospital with pathologically documented HAS were retrospectively analyzed, and the relevant differences between pure HAS (pHAS) and mixed HAS (mHAS) were determined. In addition, 141 patients with non-HAS tumors in the same T stage in the same period were selected as the control group. The data were compared between the two groups, and factors affecting the prognosis of HAS were analyzed. In addition, we included 9 patients with HAS and 27 patients with non-HAS tumors from another center for external validation. RESULTS: The patients in the HAS group were predominantly men (n = 33), and the tumor location was mostly the cardia or fundus (n = 27). Between the HAS and non-HAS groups, there were observed differences in terms of: sex, serum alpha-fetoprotein (AFP), carbohydrate antigen (CA)-125, and CA-724 levels; longest tumor diameter; degree of differentiation; vascular invasion; N stage, M stage, and tumor-node-metastasis (TNM) stage; thickest tumor diameter; plain CT attenuation; arterial-phase CT attenuation; CT attenuation between the venous and arterial phases; enhancement modes; and degrees of enhancement (all P < 0.05). In the data from another center for external validation, there were observed differences in terms of: age, degree of differentiation, vascular invasion, thickest tumor diameter, the ratio of arterial CT attenuation to CT attenuation of the abdominal aorta at the same level (RA), CT attenuation difference between the venous phase and arterial phase (HUv-a) (all P < 0.05). The results of the multivariate analysis revealed that the independent factors for differentiation were serum AFP level (P = 0.001), M stage (P = 0.038), and tumor enhancement on CT (P = 0.014). Among patients in the HAS group, 72.34% had pHAS and 27.66% had mHAS. The thickest tumor diameter and the longest short diameter of the metastatic lymph nodes of the mHAS group were on average 6.39 cm and 1.45 cm, respectively, which were larger than those in the pHAS group. The median progression-free survival time was 18.25 months in the HAS group, which was shorter than that in the non-HAS group (72.96 months; P = 0.001). The median overall survival time in the HAS group was 24.80 months, which was shorter than that in the non-HAS group (67.96 months; P = 0.001). The factors affecting the prognosis of HAS were M stage (P = 0.001), overall TNM stage (P = 0.048), presence of vascular cancer emboli (P = 0.040), and pHAS type (P = 0.046). Multifactorial analysis revealed that M stage (P = 0.027) and pHAS type (P = 0.009) were independent risk factors affecting the prognosis of HAS. CONCLUSION: Although HAS is a rare clinical entity, it should be considered in the differential diagnosis of gastric tumors. Patients with HAS often have advanced-stage disease at presentation and a worse prognosis than patients with non-HAS tumors. CT findings, combined with laboratory results, can support the diagnosis of HAS. However, the final diagnosis needs to be confirmed with a histopathologic examination. If the postoperative pathologic findings reveal the mHAS type, a rapid clinical intervention and a detailed follow-up with CT are essential.