Combining stable carbon isotope analysis and petroleum-fingerprinting to evaluate petroleum contamination in the Yanchang oilfield located on loess plateau in China

This study evaluated petroleum contamination in the Yanchang (Shaanxi Yanchang Petroleum (Group) Co., Ltd.) oilfield, located in the loess plateau region of northern Shaanxi, China. Surface soil and sediment samples were collected from the wasteland, farmland, and riverbed in this area to assess the following parameters: total petroleum hydrocarbon (TPH), n-alkanes, polycyclic aromatic hydrocarbons (PAHs), and carbon isotope ratios (delta C-13). The results showed that TPH and PAH levels in the study area were 907-3447 mg/kg and 103.59-563.50 mu g/kg, respectively, significantly higher than the control samples (TPH 224 mg/kg, PAHs below method quantification limit, MQL). Tests using delta C-13 to detect modified TPH (2238.66 to 6639.42 mg/kg) in the wastelands adjacent to the oil wells revealed more significant contamination than tests using extraction gravimetric analysis. In addition, "chemical fingerprint" indicators, such as low to high molecular weight (LMW/HMW) hydrocarbons, carbon preference index (CPI), and pristine/phytane (Pr/Ph), further confirmed the presence of heavy petroleum contamination and weathering. This has resulted in a nutrient imbalance and unsuitable pH and moisture conditions for microbial metabolic activities. This study evaluates petroleum contamination, which can inform contamination remediation on a case by case basis

Simple parameter-free self-attention approximation

The hybrid model of self-attention and convolution is one of the methods to lighten ViT. The quadratic computational complexity of self-attention with respect to token length limits the efficiency of ViT on edge devices. We propose a self-attention approximation without training parameters, called SPSA, which captures global spatial features with linear complexity. To verify the effectiveness of SPSA combined with convolution, we conduct extensive experiments on image classification and object detection tasks

Biomechanical analysis of the Maxillary Sinus Floor Membrane During internal Sinus Floor Elevation With Implants at Different angles of the Maxillary Sinus angles

OBJECTIVE: This study analyzed and compared the biomechanical properties of maxillary sinus floor mucosa with implants at three different maxillary sinus angles during a modified internal sinus floor elevation procedure. METHODS: 3D reconstruction of the implant, maxillary sinus bone, and membrane were performed. The maxillary sinus model was set at three different angles. Two internal maxillary sinus elevation models were established, and finite element analysis was used to simulate the modified maxillary sinus elevation process. The implant was elevated to 10 mm at three maxillary sinus angles when the maxillary sinus floor membrane was separated by 0 and 4 mm. The stress of the maxillary sinus floor membrane was analyzed and compared. RESULTS: When the maxillary sinus floor membrane was separated by 0 mm and elevated to 10 mm, the peak stress values of the implant on the maxillary sinus floor membrane at three different angles were as follows: maxillary sinus I: 5.14-78.32 MPa; maxillary sinus II: 2.81-73.89 MPa; and maxillary sinus III: 2.82-51.87 MPa. When the maxillary sinus floor membrane was separated by 4 mm and elevated to 10 mm, the corresponding values were as follows: maxillary sinus I: 0.50-7.25 MPa; maxillary sinus II: 0.81-16.55 MPa; and maxillary sinus III: 0.49-22.74 MPa. CONCLUSION: The risk of sinus floor membrane rupture is greatly reduced after adequate dissection of the maxillary sinus floor membrane when performing modified internal sinus elevation in a narrow maxillary sinus. In a wide maxillary sinus, the risk of rupture or perforation of the wider maxillary sinus floor is reduced, regardless of whether traditional or modified internal sinus elevation is performed at the same height

Physical conditions of molecular gas in the Circinus galaxy: Multi-J CO and CI 1-0 observations

We report mapping observations of the $^{12}$CO $J=3-2$, $4-3$, $6-5$, and $7-6$ transitions and the CI 492 GHz transition toward the central 40$''\times$40$''$ region of the Circinus galaxy, using the Atacama Pathfinder EXperiment (APEX) telescope. We also detected $^{13}$CO $J=3-2$ at the central position of Circinus. These observations are to date the highest CO transitions reported in Circinus. With large velocity gradient (LVG) modeling and likelihood analysis we try to obtain density, temperature, and column density of the molecular gas in three regions: the nuclear region ($D< 18''\sim$ 360 pc), the entire central 45$''$ ($D<45''\sim$ 900pc) region, and the star-forming (S-F) ring (18$''<D<45''$). In the nuclear region, we can fit the CO excitation with a single excitation component, yielding an average condition of $n_{\rm H_2} \sim 10^{3.2}$cm$^{-3}$, $T_{\rm kin}$ $\sim$ 200 K, and d$v$/d$r \sim$ 3 km s$^{-1}$pc$^{-1}$. In the entire 45$''$ region, two excitation components are needed with $n_{\rm H_2}$ $\sim$ 10$^{4.2}$ and 10$^{3.0}$ cm$^{-3}$, $T_{\rm kin}\sim$ 60 K and 30 K, and $M_{\rm H_2}\sim$ $2.3\times 10^7$ M$_\odot$ and $6.6 \times 10^7$ M$_\odot$, respectively. The gas excitation in the S-F ring can also be fitted with two LVG components, after subtracting the CO fluxes in the 18$''$ region. The S-F ring region contributes 80\% of the molecular mass in the 45$''$ region. For the 45$''$ region, we find a conversion factor of $N({\rm H_2})/I_{\rm CO\ 1-0}$ = $0.37\times 10^{20}$ cm$^{-2} ({\rm K\ km\ s}^{-1})^{-1}$, about 1/5 of the Galactic disk value. The luminosity ratios of CI and $^{12}$CO $J=3-2$ ($R_{\rm CI/CO\ J=3-2}$) in Circinus basically follow a linear trend. The average $R_{\rm CI/CO\ J=3-2}$ in Circinus is $\sim$ 0.2, lying at an intermediate value between non-AGN nuclear region and high-redshift galaxies.Comment: 18 pages, 17 figures. A&A accepte

Professional support during the postpartum period: primiparous mothers' views on professional services and their expectations, and barriers to utilizing professional help.

BACKGROUND:Primiparous mothers who lack of experience and knowledge of child caring, are usually overwhelmed by multifarious stressors and challenges. Although professional support is needed for primiparas, there is a gap between the necessary high-quality services and the currently provided poor services. This study aimed to explore Chinese primiparous mothers' views on professional services, identify barriers to utilizing professional support, and further understand mothers' expectations of and preferences for the delivery of professional services. METHOD:A descriptive phenomenological study design was utilized in this study, and semi-structured interviews were conducted with 28 primiparous mothers who had given birth in the first year period before the interview and were selected from two community health centres in Xi'an city, Shaanxi Province, Northwest China. Each conversational interview lasted between 20 and 86 min. Colaizzi's seven-step phenomenological approach was used to analyse the data. RESULTS:Three major themes were identified: (a) dissatisfaction with current professional services for postpartum mothers, (b) likelihood of health care professional help-seeking behaviour, (c) highlighting the demands for new health care services. The related seven sub-themes included being disappointed with current hospital services; distrusting services provided by community health centres, private institutes and commercial online platforms; preferring not seeking help from professionals as their first choice; hesitating to express their inner discourse to professionals; following confinement requirement and family burden prevents mothers from seeking professional help; experiencing urgent needs for new baby-care-related services; and determining the importance of mothers' needs. The necessity of professional support in the first month after childbirth was strongly emphasized by the participants. Online professional guidance and support were perceived as the best way to receive services in this study. CONCLUSION:The results of this descriptive phenomenological study suggested that the current maternal and child health care services were insufficient and could not meet primiparous mothers' need. The results also indicated that identifying barriers and providing services focused on mothers' needs may be an effective strategy to enhance primiparous mothers' well-being, and further suggested that feasibility, convenience, and the cultural adaptability of health care services should be considered during the delivery of postpartum interventions

In Silico Syndrome Prediction for Coronary Artery Disease in Traditional Chinese Medicine

Coronary artery disease (CAD) is the leading causes of deaths in the world. The differentiation of syndrome (ZHENG) is the criterion of diagnosis and therapeutic in TCM. Therefore, syndrome prediction in silico can be improving the performance of treatment. In this paper, we present a Bayesian network framework to construct a high-confidence syndrome predictor based on the optimum subset, that is, collected by Support Vector Machine (SVM) feature selection. Syndrome of CAD can be divided into asthenia and sthenia syndromes. According to the hierarchical characteristics of syndrome, we firstly label every case three types of syndrome (asthenia, sthenia, or both) to solve several syndromes with some patients. On basis of the three syndromes' classes, we design SVM feature selection to achieve the optimum symptom subset and compare this subset with Markov blanket feature select using ROC. Using this subset, the six predictors of CAD's syndrome are constructed by the Bayesian network technique. We also design Naïve Bayes, C4.5 Logistic, Radial basis function (RBF) network compared with Bayesian network. In a conclusion, the Bayesian network method based on the optimum symptoms shows a practical method to predict six syndromes of CAD in TCM

Physical conditions of molecular gas in the Circinus galaxy Multi-J CO and Ci ^3P_1 →^3P_0 observations

We report mapping observations of the ^(12)CO J = 3 → 2, 4 → 3, 6 → 5, and 7 → 6 transitions and the Ci ^3P→^3P_0 (Ci) 492GHz transition toward the central 40" × 40" region of the Circinus galaxy, using the Atacama Pathfinder EXperiment (APEX) telescope. We also detected ^(13)COJ = 3 → 2 at the central position of Circinus. These observations are to date the highest CO transitions reported in Circinus. With large velocity gradient (LVG) modeling and likelihood analysis we try to obtain density, temperature, and column density of the molecular gas in three regions: the nuclear region (D < 18" ~ 360 pc), the entire central 45" (D < 45" ~ 900 pc) region, and the star-forming (S-F) ring (18" < D < 45"). In the nuclear region, we can fit the CO excitation with a single excitation component, yielding an average condition of n_H_2~10^(3.2) cm^(-3), T_(kin)~ 200 K, and dν/dr~3 km s^(-1) pc^(-1). In the entire 45" region, which covers both the nucleus and the S-F ring, two excitation components are needed with n_H_2~ 10^(4.2) cm^(-3) and 10^(3.0) cm^(-3), T_(kin)~ 60 K and 30 K, and M_H_2~2.3 × 10^7 M_⊙ and 6.6 × 10^7 M_⊙, respectively. The gas excitation in the S-F ring can also be fitted with two LVG components, after subtracting the CO fluxes in the 18" nuclear region. The S-F ring region contributes 80% of the molecular mass in the 45" region. For the entire 45" region, we find a standard conversion factor of N(H_2) /I_(CO 1 → 0) = 0.37 × 10^(20)cm^(-2)(K km s^(-1))^(-1), about 1/5 of the Galactic disk value. The luminosity ratios of Ci and ^(12)COJ = 3 → 2 (R_(CI/CO 3 → 2)) in Circinus basically follow a linear trend, similar to that obtained in high-redshift galaxies. The average R_(CI/CO J = 3 → 2) in Circinus is found to be ~0.2, lying at an intermediate value between non-AGN nuclear regions and high-redshift galaxies

A survey of blockchain and artificial intelligence for 6G wireless communications

The research on the sixth-generation (6G) wireless communications for the development of future mobile communication networks has been officially launched around the world. 6G networks face multifarious challenges, such as resource-constrained mobile devices, difficult wireless resource management, high complexity of heterogeneous network architectures, explosive computing and storage requirements, privacy and security threats. To address these challenges, deploying blockchain and artificial intelligence (AI) in 6G networks may realize new breakthroughs in advancing network performances in terms of security, privacy, efficiency, cost, and more. In this paper, we provide a detailed survey of existing works on the application of blockchain and AI to 6G wireless communications. More specifically, we start with a brief overview of blockchain and AI. Then, we mainly review the recent advances in the fusion of blockchain and AI, and highlight the inevitable trend of deploying both blockchain and AI in wireless communications. Furthermore, we extensively explore integrating blockchain and AI for wireless communication systems, involving secure services and Internet of Things (IoT) smart applications. Particularly, some of the most talked-about key services based on blockchain and AI are introduced, such as spectrum management, computation allocation, content caching, and security and privacy. Moreover, we also focus on some important IoT smart applications supported by blockchain and AI, covering smart healthcare, smart transportation, smart grid, and unmanned aerial vehicles (UAVs). Moreover, we thoroughly discuss operating frequencies, visions, and requirements from the 6G perspective. We also analyze the open issues and research challenges for the joint deployment of blockchain and AI in 6G wireless communications. Lastly, based on lots of existing meaningful works, this paper aims to provide a comprehensive survey of blockchain and AI in 6G networks. We hope this surve..