Characterization of three lamp genes from largemouth bass (Micropterus salmoides): molecular cloning, expression patterns, and their transcriptional levels in response to fast and refeeding strategy.

Lysosomes-associated membrane proteins (LAMPs), a family of glycosylated proteins and major constituents of the lysosomal membranes, play a dominant role in various cellular processes, including phagocytosis, autophagy and immunity in mammals. However, their roles in aquatic species remain poorly known. In the present study, three lamp genes were cloned and characterized from Micropterus salmoides. Subsequently, their transcriptional levels in response to different nutritional status were investigated. The full-length coding sequences of lamp1, lamp2 and lamp3 were 1251bp, 1224bp and 771bp, encoding 416, 407 and 256 amino acids, respectively. Multiple sequence alignment showed that LAMP1-3 were highly conserved among the different fish species, respectively. 3-D structure prediction, genomic survey, and phylogenetic analysis were further confirmed that these genes are widely existed in vertebrates. The mRNA expression of the three genes was ubiquitously expressed in all selected tissues, including liver, brain, gill, heart, muscle, spleen, kidney, stomach, adipose and intestine, lamp1 shows highly transcript levels in brain and muscle, lamp2 displays highly expression level in heart, muscle and spleen, but lamp3 shows highly transcript level in spleen, liver and kidney. To analyze the function of the three genes under starvation stress in largemouth bass, three experimental treatment groups (fasted group and refeeding group, control group) were established in the current study. The results indicated that the expression of lamp1 was significant induced after starvation, and then returned to normal levels after refeeding in the liver. The expression of lamp2 and lamp3 exhibited the same trend in the liver. In addition, in the spleen and the kidney, the transcript level of lamp1 and lamp2 was remarkably increased in the fasted treatment group and slightly decreased in the refed treatment group, respectively. Collectively, our findings suggest that three lamp genes may have differential function in the immune and energetic organism in largemouth bass, which is helpful in understanding roles of lamps in aquatic species.

Chemical derivatization strategies for enhancing the HPLC analytical performance of natural active triterpenoids.

Triterpenoids widely exist in nature, displaying a variety of pharmacological activities. Determining triterpenoids in different matrices, especially in biological samples holds great significance. High-performance liquid chromatography (HPLC) has become the predominant method for triterpenoids analysis due to its exceptional analytical performance. However, due to the structural similarities among botanical samples, achieving effective separation of each triterpenoid proves challenging, necessitating significant improvements in analytical methods. Additionally, triterpenoids are characterized by a lack of ultraviolet (UV) absorption groups and chromophores, along with low ionization efficiency in mass spectrometry. Consequently, routine HPLC analysis suffers from poor sensitivity. Chemical derivatization emerges as an indispensable technique in HPLC analysis to enhance its performance. Considering the structural characteristics of triterpenoids, various derivatization reagents such as acid chlorides, rhodamines, isocyanates, sulfonic esters, and amines have been employed for the derivatization analysis of triterpenoids. This review comprehensively summarized the research progress made in derivatization strategies for HPLC detection of triterpenoids. Moreover, the limitations and challenges encountered in previous studies are discussed, and future research directions are proposed to develop more effective derivatization methods.

Long-Term Outcome of Photobiomodulation Therapy for Refractory Diabetic Wound After Secretory Carcinoma of the Parotid Gland Surgery: A Case Report.

Objective: To evaluate the efficacy and safety of photobiomodulation therapy (PBMT) in the treatment of diabetic patients with refractory wound. Background: Refractory wound is one of the most challenging clinical complications of diabetes mellitus. Studies have shown that PBMT can promote wound healing in many ways. Methods: We reported a 55-year-old male patient with refractory diabetic wound after secretory carcinoma of the parotid gland surgery responding to 810 nm laser. Results: After PBMT, the refractory diabetic wound healed gradually without adverse events. During follow-up 5-years, the healed wound remained stable and showed no signs of recurrence. Conclusions: PBMT can be potentially considered as a therapeutic method in diabetic patients with refractory diabetic wound.

Identifying the geospatial relationship of surface ozone pollution in China: Implications for key pollution control regions.

Surface ozone pollution, as a pressing environmental concern, has garnered widespread attention across China. Due to air mass transport, effective control of ozone pollution is highly dependent on collaborative efforts across neighboring regions. However, specific regions with strong internal interactions of ozone pollution are not yet well identified. Here, we introduced the Geospatial SHapley Additive exPlanation (GeoSHAP) approach, which primarily involves machine learning and geostatistical algorithms. Based on extensive atmospheric environmental monitoring data from 2017 to 2021, machine learning models were employed to train and predict ozone concentrations at the target location. The R2 values on the test sets of different scale regions all reached 0.98 in the overall condition, indicating that the core model has good accuracy and generalization ability. The results highlight key regions with high ozone geospatial relationship (OGR) index, predominantly located in the Northern District (ND), spanning the Fen-Wei Plain, the Loess Plateau, and the North China Plain, as well as within portions of the Yangtze River Delta (YRD) and the Pearl River Delta (PRD). Further investigation indicated that high geospatial relationships stem from a synergy between anthropogenic and natural factors, with anthropogenic factors serving as a pivotal element. This study revealed key regions with the most urgent need for joint control of anthropogenic sources to mitigate ozone pollution.

A Novel Air-Cooled Nd:YAG Laser for the Treatment of the Venous Lakes of the Lips.

Objective: To evaluate the therapeutic effect of a novel air-cooled Nd:YAG laser in the venous lakes of the lips (VLL). Background: The thermal injury is one of the most important issues during laser therapy for venous lakes. Methods: Six pieces of fresh pork livers were used to provide 30 regions with a diameter of 6 mm for experiment in vitro, among which 15 regions were treated by Nd:YAG laser with air cooling until the tissue turned gray-white, whereas the rest were treated without air cooling as control. The operation time of laser irradiation, the degree of temperature increase, and the depth of coagulation tissue were compared between two groups. Then, 60 VLL patients were selected for Nd:YAG laser treatment with or without air cooling. The operation time of laser irradiation, the degree of temperature increase, the postoperative pain visual analog scale (VAS) score, and the percentage of lesions removed within 1 month were compared. Results: In tissue studies, the treated group showed a longer operation time of laser irradiation (p < 0.01), a lower degree of temperature increase (p < 0.01), and there was no significant statistical difference in the depth of coagulation tissue (p = 0.624). In clinical studies, the treated group showed a longer operation time of laser irradiation (p < 0.01), a lower degree of temperature increase (p < 0.01), and a lower VAS score on the 1st and 2nd day, compared with the control group (p < 0.01). Conclusions: Air cooling during Nd:YAG laser for the treatment of VLL can prolong the surgical time, but lowered tissue temperature and reduced patient pain within 2 days under the premise of ensuring the treatment effect.

Preclinical Investigations on Anti-fibrotic Potential of Long-Term Oral Therapy of Sodium Astragalosidate in Animal Models of Cardiac and Renal Fibrosis.

In traditional Chinese medicine, Radix Astragali has played a vital role in treating progressive fibrotic diseases. One of its main active components, astragaloside IV, is a promising anti-fibrotic treatment despite its extremely low bioavailability. Our study aimed to optimize sodium astragalosidate (SA) by salt formation to improve solubility and oral absorption for anti-fibrotic therapy in vivo. Isoproterenol-induced myocardial fibrosis rat models and obese BKS-db mice presenting diabetic kidney fibrosis were used in this study. Daily oral administration of SA (20 mg/kg) for 14 days ameliorated cardiac fibrosis by reducing collagen accumulation and fibrosis-related inflammatory signals, including TNF-α, IL-1ß, and IL-6. In db/db mice, SA (5,10, and 20 mg/kg per day for 8 weeks) dose-dependently alleviated lipid metabolism impairment and renal dysfunction when administered orally. Furthermore, Western blot and immunohistochemistry analyses demonstrated that SA treatment inhibited renal fibrosis by suppressing TGF-ß1/Smads signaling. Taken together, our findings provide the oral-route medication availability of SA, which thus might offer a novel lead compound in preclinical trial-enabling studies for developing a long-term therapy to treat and prevent fibrosis.

Coarse particles compensate for missing daytime sources of nitrous acid and enhance atmospheric oxidation capacity in a coastal atmosphere.

Large missing sources of daytime atmospheric nitrous acid (HONO), a vital source of hydroxyl radicals (OH) through its photolysis, frequently exist in global coastal regions. In this study, ambient HONO and relevant species were measured at a coastal site in the Pearl River Delta (PRD), China, during October 2019. Relatively high concentrations (0.32 ± 0.19 ppbv) and daytime peaks at approximately 13:00 of HONO were observed, and HONO photolysis was found to be the dominant (55.5 %) source of the primary OH production. A budget analysis of HONO based on traditional sources suggested large unknown sources during the daytime (66.4 %), which had a significant correlation with the mass of coarse particles (PM2.5-10) and photolysis frequency (J(NO2)). When incorporating photolysis of the abundant nitrate measured in coarse particles with a reasonable enhancement factor relative to fine particles due to favorable aerosol conditions, the missing daytime sources of HONO could be fully compensated by coarse particles serving as the largest source at this coastal site. Our study revealed great potential of coarse particles as a strong daytime HONO source, which has been ignored before but can efficiently promote NOx recycling and thus significantly enhance atmospheric oxidation capacity.

Functional connectivity alterations in the frontoparietal network and sensorimotor network are associated with behavioral heterogeneity in blepharospasm.

Objective: Primary blepharospasm (BSP) is a clinically heterogeneous disease that manifests not only as spasmodic closure of the eyelids but also sometimes with apraxia of eyelid opening (AEO). This cross-sectional study aimed to investigate differences in the neural mechanisms of isolated BSP and BSP-associated AEO subtypes, which may reveal the pathophysiology underlying different phenotypes. Methods: A total of 29 patients manifested as isolated BSP, 17 patients manifested as BSP associated with AEO, and 28 healthy controls underwent resting-state functional near-infrared spectroscopy (fNIRS). We assessed functional connectivity (FC) between regions of interest (ROIs) in the fronto-parietal control network (PFCN) and sensorimotor network (SMN). We also examined the relationship between altered FC and behavioral data. Results: In the FPCN, ROI- analyses showed decreased FC between the left premotor cortex and supramarginal gyrus in the BSP with AEO group compared to the isolated BSP group. In the SMN, both subgroups showed hypoconnectivity of the left premotor cortex with the right primary motor cortex, primary sensory cortex, and somatosensory association cortex. This hypoconnectivity was positively correlated with the total number of botulinum toxin A treatments, which suggests that long-term botulinum toxin A treatment may modulate motor sequence planning and coordination. Conclusion: These findings showed different connectivity alterations in neural networks associated with motor and cognitive control among different behavioral phenotypes of BSP. The identification of specific alterations in various networks that correspond to clinical heterogeneity may inform the identification of potential biomarkers for early diagnosis and personalized neuromodulation targets for treating different BSP subphenotypes.

Evaluation of the accuracy of cone-beam computed tomography image segmentation of isolated tooth roots based on the dynamic threshold method.

OBJECTIVE: Accurate quantification of the root surface area (RSA) plays a decisive role in the advancement of periodontal, orthodontic, and restorative treatment modalities. In this study, we aimed to develop a dynamic threshold-based computer-aided system for segmentation and calculation of the RSA of isolated teeth on cone-beam computed tomography (CBCT) and to assess the accuracy of the measured data. METHOD: We selected 24 teeth to be extracted, including single-rooted and multi-rooted teeth, from 22 patients who required tooth extraction. In the experimental group, we scanned 24 isolated teeth using CBCT with a voxel size of 0.3 mm. We designed a computer-aided system based on a personalized dynamic threshold algorithm to automatically segment the roots of 24 isolated teeth in CBCT images and calculate the RSA. In the control group, we employed digital intraoral scanner devices to perform optical scanning on 24 isolated teeth and subsequently manually segmented the roots using 3-matic software to calculate the RSA. We used the paired t-test (P < 0.05) and Bland-Altman plots to analyze the consistency of the two measurement methods. RESULTS: The results of the paired t-test showed that there was no significant difference in the RSAs obtained using the dynamic threshold method and the optical scanning image reconstruction (t = 1.005, P = 0.325 > 0.05). As per the Bland-Altman plot, the results were evenly distributed within the region of ± 1.96 standard deviations of the mean, with no increasing or decreasing trends and good consistency. CONCLUSION: In this study, we designed a computer-aided root segmentation system based on a personalized dynamic threshold algorithm to automatically segment the roots of isolated teeth in CBCT images with a voxel size of 0.3 mm. We found that the RSA calculated using this approach was highly accurate, and a voxel of 0.3 mm in size could accurately display the surface area data in CBCT images. Overall, our findings in this study provide a foundation for future work on accurate automatic segmentation of tooth roots in full-mouth CBCT images and the computation of RSA.

Correlation of idiopathic benign paroxysmal positional vertigo with cerebral small vessel disease.

BACKGROUND: Benign paroxysmal positional vertigo (BPPV) is the most prevalent form of peripheral vertigo, with vascular lesions being one of its suspected causes. The older adults are particularly vulnerable to BPPV. Cerebral small vessel disease (CSVD), on the other hand, is a clinical condition that results from damage of cerebral small vessels. Vascular involvement resulting from age-related risk factors and proinflammatory state may act as the underlying factor linking both BPPV and CSVD. AIM: The objective of this study is to explore the potential correlation between BPPV and CSVD by examining whether individuals aged 50 and older with BPPV exhibit a greater burden of CSVD. MATERIALS AND METHODS: This retrospective study included patients aged 50 years and older who had been diagnosed with BPPV. A control group consisting of patients diagnosed with idiopathic facial neuritis (IFN) during the same time period was also included. The burden of cerebral white matter hyperintensities (WMHs) was evaluated using the Fazekas scale. An ordinal regression analysis was conducted to investigate the potential correlation between BPPV and WMHs. RESULTS: The study included a total of 101 patients diagnosed with BPPV and 116 patients with IFN. Patients with BPPV were found to be significantly more likely (OR = 2.37, 95% CI 1.40-4.03, p = 0.001) to have a higher Fazekas score compared to the control group. Brain infarctions, hypertension, and age were all identified as significant predictors of white matter hyperplasia on MRI, with OR of 9.9 (95% CI 4.21-24.84, P<0.001), 2.86 (95% CI 1.67-5.0, P<0.001), and 1.18 (95% CI 1.13-1.22, P<0.001) respectively. CONCLUSION: Our findings suggest that vascular impairment caused by age-related risk factors and proinflammatory status may be contributing factors to the development of BPPV in individuals aged 50 and above, as we observed a correlation between the suffering of BPPV and the severity of WMHs.

Key drivers to heterogeneity evolution of black carbon-containing particles in real atmosphere.

The evolution of black carbon (BC) particles during atmospheric aging led to the complexity of their environmental and climate effect assessment. This study simultaneously measured the heterogeneous distribution of multi-level microphysical properties of BC-containing particles (i.e., BC mass concentration, coating amounts, and morphology) by a suite of state-of-the-art instruments, and investigated how atmospheric processing influence these heterogeneities. Our field measurements show that the mixing states of atmospheric BC-containing particles exhibit a clear dependence on BC core diameters. The particles with small BC core sizes (80-160 nm) are coated and reshaped more rapidly in real atmosphere, with coating-to-BC mass ratios (MR) and non-spherical fractions of 5.1 ± 1.2 and 61 ± 19 %, respectively. Conversely, the particles with large core sizes (240-320 nm) are thinly coated and fractal, with MR and non-spherical fractions of 4.0 ± 0.3 and 74 ± 15 %, respectively. Furthermore, primary emissions result in low heterogeneity in coating amount but great heterogeneity in morphology between BC-containing particles of different sizes, while photochemical processing would enhance heterogeneity in coating amount but weaken the heterogeneity in morphology. Overall, our field measurement of multi-level microphysical properties highlights that BC core size and atmospheric processing are the key factors that drive the heterogeneity evolution of BC-containing particles in real atmosphere.

Application Value of 64-slice Multidetector Spiral CT Contrast-enhanced Scan in Maxillofacial Soft Tissue Hypervascular Tumours.

OBJECTIVE: To evaluate the diagnostic ability and clinical imaging features in maxillofacial soft tissue hypervascular tumours by 64-slice multidetector spiral computed tomography (64-MDCT) contrast-enhanced scanning. METHODS: In a retrospective study of 21 cases of hypervascular tumours, the degree of blood supply and indexes were assessed, and the pathological results were used as the diagnostic gold standard to evaluate the sensitivity and specificity of 64-MDCT plain scan and enhanced CT in the diagnosis of oral and maxillofacial soft tissue hypervascular tumours, using the receiver operating characteristic curve to analyse and evaluate the efficacy. RESULTS: Among 21 patients, the diagnostic accuracy of 64-MDCT contrast-enhanced scan was 90.48%, the area under the curve of venous phase CT value was 0.80, the sensitivity was 83.30% and the specificity was 72.73%. CONCLUSION: 64-MDCT contrast-enhanced scan can be used to evaluate the blood supply of maxillofacial soft tissue hypervascular tumours before an operation. The CT value in the venous phase of tumours has the highest diagnostic effectiveness, which can reduce the risk of blood loss during surgery for maxillofacial hypervascular tumours. In addition, it has certain guiding significance for the formulation of clinical treatment plans.

Ultrasound-guided pacemaker implantation at the bedside: A lifesaving technique for cardiac emergencies.

OBJECTIVE: To investigate the safety and effectiveness of implanting temporary pacemakers using ultrasound-guidance at the bedside for rescuing patients in case of cardiac emergencies. METHODS: We enrolled 194 patients with cardiac emergencies requiring temporary pacemakers in this study, and randomly assigned them to either a bedside ultrasound-guided installation group or an electrocardiogram-guided installation group. There were 105 cases in the bedside ultrasound-guided installation group, aged approximately 66.3 ± 10.2 years, and 89 cases in the electrocardiogram-guided installation group, aged approximately 65.8 ± 9.5 years old, and disease composition was similar between the two groups. We then compared the duration of the procedure, success rates, and occurrence of adverse events between the two groups. RESULTS: The two groups showed similar clinical characteristics. The success rates of venipuncture and temporary pacemaker electrode placement were both 100% in the bedside ultrasound-guided installation group, compared to 87.8% and 96.7% respectively, in the electrocardiogram-guided installation group, with a statistically significant difference between the two groups. The duration of puncture was significantly shorter in the bedside ultrasound-guided installation group than in the electrocardiogram-guided installation group, with statistically significant differences. Moreover, no adverse events such as hematoma, pneumothorax and electrode dislodgement occurred in the bedside ultrasound-guided installation group, while 13 cases in the electrocardiogram-guided installation group experienced adverse events, and the difference was statistically significant. CONCLUSIONS: The bedside installation of temporary pacemakers using ultrasound guidance is a simple, safe, effective, and cost-efficient procedure that boasts a high success rate, does not involve radiation, and enables accurate placement of the electrode catheter.

Seasonal variation characteristics of atmospheric peroxyacetyl nitrate (PAN) and its source apportionment in a megacity in southern China.

Owing to its biotoxicity and inductive effect on photochemical pollution, atmospheric peroxyacetyl nitrate (PAN), which is a typical product of atmospheric photochemical reactions, has attracted much research attention. However, to the best of our knowledge, few comprehensive studies have been conducted on the seasonal variation and key influencing factors of PAN concentrations in southern China. In this study, PAN, ozone (O3), precursor volatile organic compound (VOC), and other pollutant concentrations were measured online for 1 year (from October 2021 to September 2022) in Shenzhen, a megacity in the Greater Bay Area of China. The average concentrations of PAN and peroxypropionyl nitrate (PPN) were 0.54 and 0.08 parts per billion (ppb), and the maximum hourly concentrations reached 10.32 and 1.01 ppb, respectively. The results of the generalized additive model (GAM) showed that the atmospheric oxidation capacity and precursor concentration were the most important factors affecting the PAN concentration. According to the steady-state model, the average cumulative contribution to the peroxyacetyl (PA) radical formation rate by six major carbonyl compounds was calculated at 4.2 × 106 molecules cm-3 s-1, and acetaldehyde (63.0 %) and acetone (13.9 %) contributed the most. Furthermore, the photochemical-age-based parameterization method was used to analyze the source contributions of carbonyl compounds and PA radicals. The results showed that although the primary anthropogenic (40.2 %), biogenic (27.8 %), and secondary anthropogenic (16.4 %) sources were the most important contributors of PA radicals, the biogenic and secondary anthropogenic source contributions both increased considerably in summer, and the cumulative proportion of both sources reached ~70 % in July. In addition, a comparison of PAN pollution processes in different seasons revealed that in summer and winter, the PAN concentration was predominantly limited by precursors and meteorological parameters, such as light intensity, respectively.

Feasibility of mini-implant insertion between mesial and distal buccal roots of a maxillary first molar: A cone-beam computed tomography imaging study.

INTRODUCTION: Mini-implant insertion in the maxillary posterior region can be influenced by anatomic limitations, thus increasing the failure rate. We explored the feasibility of a new implantation site: the region between the mesial and distal buccal roots of the maxillary first molar. METHODS: Cone-beam computed tomography data from 177 patients were collected from a database. The maxillary first molars were morphologically classified by analyzing the angle and morphology of the mesial and distal buccal roots. Next, 77 subjects were randomly selected from the 177 patients to measure and analyze the hard-tissue morphology in the maxillary posterior region. RESULTS: We devised the Morphological Classification on the Mesial and Distal Buccal Roots of Maxillary First Molar (MCBRMM), divided into 3 types: MCBRMM-I, II, and III. In all subjects, MCBRMM-I, II, and III accounted for 43%, 25%, and 32%, respectively. At 8 mm from the mesial cementoenamel junction of maxillary first molars, the interradicular distance between the maxillary first molar's mesiodistal buccal roots of MCBRMM-I was 2.6 mm, showing an upward trend from the cementoenamel junction to the apex. The distance from the buccal bone cortex to the palatal root was >9 mm. The buccal cortical thickness was >1 mm. CONCLUSIONS: This study provided a potential site for mini-implant insertion in the maxillary posterior region: the alveolar bone of maxillary first molars in MCBRMM-I.

Investigation of periodontal status and bacterial composition aroundmini-implants.

INTRODUCTION: Mini-implants are now widely used in orthodontic treatment. Soft-tissue inflammation around the mini-implant is an important factor affecting its stability. This study aimed to investigate the periodontal status and the bacterial composition around mini-implants. METHODS: A total of 79 mini-implants in 40 patients (aged 18-45 years) were evaluated in this study. The mini-implant probing depth (mPD), mini-implant gingival sulcus bleeding index (mBI), mini-implant plaque index (mPLI), and the composition of the supragingival and subgingival plaque around the mini-implants were recorded. After Congo red staining, the bacteria were classified and counted under a light microscope. RESULTS: The mPLI and mBI around mini-implants in the infrazygomatic crest were higher than those in the buccal shelf and interradicular area. The mPD was higher on the coronal site of the mini-implant than on the mesial, distal, and apical sites in the infrazygomatic crest. The mPLI around the mini-implant was positively correlated with the mBI, and the mBI was positively correlated with the mPD. The supragingival and subgingival bacterial composition around the mini-implants was similar to that of natural teeth. Compared with supragingival bacterial composition, the subgingival bacteria of mini-implants had a significantly lower proportion of cocci and a higher proportion of bacilli and spirochetes. CONCLUSIONS: The bacteria composition of the plaque and the location are important factors in the inflammation around mini-implants. Similar to natural teeth, mini-implants require health maintenance to prevent inflammation of the surrounding soft tissue and maintain stability.

Evolution characteristic of atmospheric black carbon particles at a coastal site in the Pearl River Delta, China.

The mixing of black carbon (BC) with secondary materials is a major uncertainty source in assessing its radiative forcing. However, current understanding of the formation and evolution of various BC components is limited, particularly in the Pearl River Delta, China. This study measured submicron BC-associated nonrefractory materials and the total submicron nonrefractory materials using a soot particle aerosol mass spectrometer and a high-resolution time-of-flight aerosol mass spectrometer, respectively, at a coastal site in Shenzhen, China. Two distinct atmospheric conditions were also identified to further explore the distinctive evolution of BC-associated components: polluted period (PP) and clean period (CP). Comparing the components of two particles, we found that more-oxidized organic factor (MO-OOA) prefers to form on BC during PP rather CP. The formation of MO-OOA on BC (MO-OOABC) was affected by both enhanced photochemical processes and nocturnal heterogeneous processes. Enhanced photo-reactivity of BC, photochemistry during the daytime, and heterogeneous reaction at nighttime were potential pathways for MO-OOABC formation during PP. The fresh BC surface was favorable for the formation of MO-OOABC. Our study shows the evolution of BC-associated components under different atmospheric conditions, which should be considered in regional climate models to improve the assessment of the climate effects of BC.

Characterizing formation mechanisms of secondary aerosols on black carbon in a megacity in South China.

Refractory black carbon (rBC) aerosols emitted from incomplete combustion are important climate forcers. Understanding the chemical characteristics and evolution of rBC-related components is particularly crucial to assess rBC environmental impacts. Here, we explored the chemical components of rBC in Shenzhen, China, using a soot-particle aerosol mass spectrometer (SP-AMS). The observations showed that the rBC coating was mainly composed of secondary aerosols with an average mass contribution of 84.7 %. Among them, secondary organic coating occupied ∼57.7 % of the total coating mass. Exploration of the relationship between secondary organic aerosol (SOA) coating and Ox (=NO2 + O3, an indicator of the extent of photochemical processing) showed that SOA coating was generated mainly through photochemical oxidation during the day. Similarly, sulfate coating, with a small mass fraction of 0.9 %, was also dominated by photochemical oxidation. In contrast, nitrate coating responded positively to ambient relative humidity, especially at night, indicating that it was driven by heterogeneous reactions. In addition, the increased ratio of nitrate on rBC to bulk nitrate at night suggested that black carbon surface could facilitate nocturnal nitrate formation.

A novel machine learning method for evaluating the impact of emission sources on ozone formation.

Ambient ozone air pollution is one of the most important environmental challenges in China today, and it is particularly significant to identify pollution sources and formulate control strategies. In present study, we proposed a novel method of positive matrix factorization-SHapley Additive explanation (PMF-SHAP) for evaluating the impact of emission sources on ozone formation, which can quantify the main emission sources of ozone pollution. In this method, we first used the PMF model to identify the source of volatile organic compounds (VOCs), and then quantified various emission sources using a combination of machine learning (ML) models and the SHAP algorithm. The R2 of the optimal ML model in this method was as high as 0.96, indicating that the prediction performance was excellent. Furthermore, we explored the impact of different emission sources on ozone formation, and found that ozone formation in Shenzhen was more affected by VOCs, of which vehicle emission sources may have the greatest impact. Our results suggest that the appropriate combination of traditional models with ML models can well address environmental pollution problems. Moreover, the conclusions obtained based on the PMF-SHAP method were different from the traditional ozone formation potential (OFP) results, providing valuable clues for related mechanism studies.

Oral and maxillofacial pain as the first sign of metastasis of an occult primary tumour: A fifteen-year retrospective study.

BACKGROUND: Metastatic adenocarcinoma of the jaw (MAJ) is a rare disease that accounts for 1%-3% of all oral and maxillofacial malignant tumours. Oral and maxillofacial pain may be the first symptom of metastatic spread of an occult primary tumour. Therefore, early identification of oral and maxillofacial pain by dental professionals is critical. AIM: To explore the clinical and computerized tomography (CT) features of MAJ with oral and maxillofacial pain as the first symptom. METHODS: The medical records of all patients who were treated in our hospital between January 2006 and February 2020, and diagnosed with MAJ with oral and maxillofacial pain as the first symptom, were reviewed retrospectively. Clinical data were collected on age, sex, medical history, clinical manifestations, site of metastasis, and site of the primary lesion. CT features were analysed in detail, and a radiological classification scheme comprising five types: Osteolytic, osteoblastic, mixed, cystic, and alveolar bone resorption was proposed. RESULTS: The primary sites of MAJ were the lungs (n = 6), liver (n = 4), kidneys (n = 2), prostate (n = 1), and gastric cardia (n = 1). Five tumours were classified as the osteolytic type, all with a permeative margin (100%, P < 0.05), and three were classified as the mixed type, mostly with a moth-eaten margin (80%, P < 0.05). The cystic (n = 3) and alveolar bone resorption (n = 1) types had geographic margins, and the osteoblastic type (n = 1) had sclerotic margins. Moreover, nine tumours showed periosteal reaction and five showed a localised soft tissue mass, while the occurrence of jaw expansion was relatively rare. CONCLUSION: MAJ has complex clinical and CT features. Oral and maxillofacial pain may be the first sign of a primary tumour affecting other sites.