Investigation of formaldehyde sources and its relative emission intensity in shipping channel environment.

Formaldehyde (HCHO) is considered one of the most abundant gas-phase carbonyl compounds in the atmosphere, which can be directly emitted through transportation sources. Long-Path Differential Optical Absorption Spectroscopy (LP-DOAS) was used to observe HCHO in the river channel of Wusong Wharf in Shanghai, China for the whole year of 2019. Due to the impact of ship activity, the annual average HCHO level in the channel is about 2.5 times higher than that in the nearby campus environment. To explain the sources of HCHO under different meteorological conditions, the tracer-pair of CO and Ox (NO2+O3) was used on the clustered air masses. The results of the source appointment show that primary, secondary and background account for 24.14% (3.34 ± 1.19 ppbv), 44.78% (6.20 ± 2.04 ppbv) and 31.09% (4.31 ± 2.33 ppbv) of the HCHO in the channel when the air masses were from the mixed direction of the city and channel, respectively. By performing background station subtraction at times of high primary HCHO values and resolving the plume peaks, directly emitted HCHO/NO2 in the channel environment and plume were determined to be mainly distributed between 0.2 and 0.3. General cargo ships with higher sailing speeds or main engine powers tend to have higher HCHO/NO2 levels. With the knowledge of NO2 (or NOx) emission levels from ships, this study may provide data support for the establishment of HCHO emission factors.

Disposable Polypropylene Face Masks: A Potential Source of Micro/Nanoparticles and Organic Contaminates in Humans.

We have been effectively protected by disposable propylene face masks during the COVID-19 pandemic; however, they may pose health risks due to the release of fine particles and chemicals. We measured micro/nanoparticles and organic chemicals in disposable medical masks, surgical masks, and (K)N95 respirators. In the breathing-simulation experiment, no notable differences were found in the total number of particles among mask types or between breathing intensities. However, when considering subranges, <2.5 µm particles accounted for ∼90% of the total number of micro/nanoparticles. GC-HRMS-based suspect screening tentatively revealed 79 (semi)volatile organic compounds in masks, with 18 being detected in ≥80% of samples and 44 in ≤20% of samples. Three synthetic phenolic antioxidants were quantified, and AO168 reached a median concentration of 2968 ng/g. By screening particles collected from bulk mask fabrics, we detected 18 chemicals, including four commonly detected in masks, suggesting chemical partition between the particles and the fabric fibers and chemical exposure via particle inhalation. These particles and chemicals are believed to originate from raw materials, intentionally and nonintentionally added substances in mask production, and their transformation products. This study highlights the need to study the long-term health risks associated with mask wearing and raises concerns over mask quality control.

[Effect of bone cement distribution on the clinical outcome of unilateral transpedicular puncture for spinal osteoporotic fractures].

OBJECTIVE: To investigate the effects of different bone cement morphology distribution on the clinical efficacy of unilateral percutaneous vertebroplasty(PVP) for spinal osteoporotic fractures. METHODS: The clinical data of 66 patients with osteoporotic vertebral compression fractures received unilateral PVP treatment from January 2019 to April 2020 were retrospectively analyzed. There were 16 males and 50 females, including 83 vertebral bodies, 45 thoracic vertebrae and 38 lumbar vertebrae, and 55 patients with single-segment, 6 double-segment, 4 three-segment and 1 four-segment. The age ranged from 60 to 93 years with an average of (76.83±8.65) years. The included patients were admitted to hospital 1 to 10 days after onset, and were diagnosed by anteroposterior and lateral X-rays, MRI and bone density examination before surgery. According to the shape of bone cement in postoperative X-ray, the patients were divided into O-shaped group (28 cases) and H-shaped group (38 cases). In O-shaped group, the bone cement presented agglomeration mass distribution in the affected vertebra in postoperative X-ray while the bone cement presented disseminated honeycomb distribution in the affected vertebrae in H-shaped group. Bone cement injection volume was collected in two groups. The intraoperative bone cement leakage and postoperative adjacent vertebral fractures were observed. The VAS of the two groups before operation and 1 day, 1 month, 6 months and 1 year after operation were compared;and ODI of the two groups 1 day, 6 months and 1 year after operation were compared. The kyphosis angle and anterior height of the affected vertebrae were measured before operation and 1 week, 1 year after operation. RESULTS: All 66 patients completed 1-year follow-up, and all patients healed well at the puncture site after surgery. There were 1 case and 8 cases of bone cement leakage in O-shaped group and H-shaped group during surgery respectively (P<0.05), but no serious complications occurred. One case occurred adjacent vertebral fracture in both groups during one-year follow-up (P>0.05). There was no statistical significance in injection amount of bone cement between the two groups (P>0.05). The VAS scores of O-shaped group and H-shaped group were 7.89±0.79, 2.75±1.08, 0.46±0.58, 0.36±0.49 and 8.00±1.04, 2.58±1.15, 0.53±0.56, 0.42±0.50 before operation, 1 day, 6 months, 1 year after operation respectively, and there was no statistical significance(P>0.05), and the VAS scores were 0.96±0.58 and 1.18±0.83 at 1 month after operation respectively, with statistical significance(P<0.05). The ODI scores of O-shaped group and H-shaped group were 12.43±3.78, 10.00±2.46, 8.43±1.50 and 12.11±3.68, 9.53±2.35, 8.32±1.51 at 1 day, 6 months and 1 year after surgery respectively, and there was no statistical significance between the two groups(P>0.05). There were no statistical significance in kyphotic angles and anterior height before surgery and 1 week, 1 year after surgery between two groups (P>0.05). CONCLUSION: No matter the distribution of bone cement is O-shape or H-shape, it can achieve good clinical effect, and the prognosis effect is equivalent. Therefore, when performing unilateral puncture PVP surgery, it is not necessary to deliberately increase the puncture angle of the puncture needle in order to achieve the full diffusion of the affected vertebrae, so as to reduce the risk of damaging important structures and bone cement leakage.

Effect-directed analysis of estrogenic chemicals in sediments from an electronic-waste recycling area.

Electronic waste (e-waste) pollution is of great concern due to the release of hazardous chemicals during the improper e-waste disposal. Many chemicals leached from e-waste were reported to pose estrogenic effects. To date, little is known regarding the occurrence and biological effects of estrogenic chemicals in sediments near an e-waste area. In this study, an effect-directed analysis (EDA) is applied to determine the estrogenic chemicals in sediments of four sites collected from a typical e-waste recycling city in China. Following screening with the ER-CALUX assay, the extract of sample with the most potent effect was subjected in fractionation using reverse phase liquid chromatography. Based on a target analysis for the active fractions, four compounds, including estrone, 17ß-estradiol, 17α-ethinylestradiol and bisphenol A, were identified, and these contributed to 17% of the total toxic effects in the sample. A further nontarget analysis screened four candidates, namely diethylstilbestrol (DES), hexestrol (HES), nandrolone and durabolin, and the total contribution was found to be 48% from the active sample. Specifically, DES and HES were only detected in the active sample and were found to be the primary drivers of estrogenic effects. An examination of the identified chemicals in the four sites indicated that these estrogenic chemicals may originate from e-waste recycling, livestock excretion and domestic waste. These findings uncovered the estrogenic pollutants in sediments from an e-waste area. Considering single endpoint in biological assay is not abundant to screen chemicals with different toxic effects, further EDA studies with multiple endpoints are required to better understand the occurrence of representative or unknown chemicals in e-waste-polluted areas.

Establishment and Optimization of Radiomics Algorithms for Prediction of KRAS Gene Mutation by Integration of NSCLC Gene Mutation Mutual Exclusion Information.

Purpose: To assess the significance of mutation mutual exclusion information in the optimization of radiomics algorithms for predicting gene mutation. Methods: We retrospectively analyzed 258 non-small cell lung cancer (NSCLC) patients. Patients were randomly divided into training (n = 180) and validation (n = 78) cohorts. Based on radiomics features, radiomics score (RS) models were developed for predicting KRAS proto-oncogene mutations. Furthermore, a composite model combining mixedRS and epidermal growth factor receptor (EGFR) mutation status was developed. Results: Compared with CT model, the PET/CT radiomics score model exhibited higher AUC for predicting KRAS mutations (0.834 vs. 0.770). By integrating EGFR mutation information into the PET/CT RS model, the AUC, sensitivity, specificity, and accuracy for predicting KRAS mutations were all elevated in the validation cohort (0.921, 0.949, 0.872, 0.910 vs. 0.834, 0.923, 0.641, 0.782). By adding EGFR exclusive mutation information, the composite model corrected 64.3% false positive cases produced by the PET/CT RS model in the validation cohort. Conclusion: Integrating EGFR mutation status has potential utility for the optimization of radiomics models for prediction of KRAS gene mutations. This method may be used when repeated biopsies would carry unacceptable risks for the patient.

Optimization of Enzymolysis Clearance Strategy To Enhance Renal Clearance of Radioligands.

The kidney is the main dose-limiting organ in radioligand therapy (RLT), and there is an urgent need for reducing renal radioactivity accumulation. According to the enzymolysis clearance strategy, the first objective of this study is to test whether enzymolysis efficiency can be improved by introducing a hydrophobic amino acid with a bulkier side chain to the second position of the cleavable sequence, and the second objective is to screen an optimal sequence to minimize the renal uptake. Four exendin 4 (Ex4) peptide analogues with different cleavable sequences were synthesized and labeled with 68Ga. Both in vitro and in vivo metabolism studies were performed using either the model compounds or the complete probes. The in vitro stabilities of the tracers were evaluated in PBS and mouse serum. The microPET images were acquired in the INS-1 tumor model at different time points, and the radioactivity uptakes of the probes in tumors and kidneys were determined and compared. All the probes were stable in both PBS and mouse serum for at least 1 h. The in vitro cleavage study for both model compounds and intact probes showed enzymolysis efficiency in the following order: MWK > MFK > MVK > MGK. The in vivo metabolism study confirmed that a fragment of 68Ga-NOTA-Met-OH appeared in both kidney and urine samples for all analogues with MVK, MFK, and MWK sequences. The microPET images showed that the tumor uptakes of all the modified probes were comparable to those of the control, while the kidney uptakes were significantly reduced by inserting the MWK, MFK, or MVK linker. The tumor-to-kidney ratios at 0.5, 1, and 2 h time points showed the following order: 68Ga-NOTA-MWK-Ex4 > 68Ga-NOTA-MFK-Ex4 > 68Ga-NOTA-MVK-Ex4. In this study, based on the enzymolysis clearance strategy and the preference of the enzyme, different sequences were designed and compared both in vitro and in vivo. The results indicated that the larger the steric hindrance of the second hydrophobic amino acid side chain, the more effective the enzymatic hydrolysis, with enzymolysis efficiency in the following order: MWK > MFK > MVK > MGK. MWK appears to be the most effective sequence in reducing renal radioactivity accumulation of exendin 4 peptide derivatives.

Upregulation of HOXC9 generates interferon-gamma resistance in gastric cancer by inhibiting the DAPK1/RIG1/STAT1 axis.

Clinical reports indicate that gastric cancer (GC) has a high mortality rate, but its pathological mechanism remains poorly understood. This work integrated bioinformatics analysis with experimental verification to explore novel biomarkers of gastric cancer. First, weighted gene coexpression network analysis was applied to screen significant genes correlated with GC development. Gene set enrichment analysis was also used to unearth the most relevant biological functions of significant genes. As a result, we discovered homeobox C9 (HOXC9) as a novel oncogene in GC, primarily through negatively regulating immune response. High expression of HOXC9 predicted a poor prognosis in GC patients, and knocking down HOXC9 efficiently enhanced the interferon-gamma (IFNγ)-dependent apoptosis in two GC cell lines as well as organoids from patients. Furthermore, cleaved caspase-3/7 and phosphorylated signal transducer and activator of transcription 1 (p-STAT1) were also significantly enhanced in HOXC9 knockdown cells and organoids treated with IFNγ. Mechanistically, we found that HOXC9 inhibited the death-associated protein kinase 1 (DAPK1) and its downstream retinoic acid-inducible gene-I (RIG1) to generate GC IFNγ resistance. In summary, we identified and confirmed that HOXC9 generates IFNγ resistance in GC by inhibiting the DAPK1/RIG1/p-STAT1 axis.