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Based on the practical problem that excessive effluent pollutants caused by the impact of soybean wastewater on urban sewage treatment system, the effect of soybean wastewater on pollutants removal in sequencing batch reactor (SBR) and emergency control measures were investigated through single cycle instantaneous wastewater impact test. The results showed that with the increase of water quality impact load, COD removal rate increased initially and then decreased, while NH4+-N and TN removal rates increased gradually. The effect of water quality impact on TP removal was relatively small. When COD of the impact wastewater was 370 mg/L, the effluent NH4+-N and TN could not meet the first level class A standard of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002). As the water volume impact increased, the changes of COD and TN removal rates remained consistent with the water quality impact, and the effect of water volume impact on NH4+-N and TP removal was relatively small. As the impact of water quality and water volume increased, the protein(PN) and polysaccharide(PS) components in extracellular polymeric substances(EPS) were both affected. Regulating the aeration rate could be used as an effective emergency control measure for the impact of soybean products wastewater. When the COD of the impact wastewater was 370 mg/L and the aeration rate was 0.9 L/min, COD, NH4+-N, TN, and TP could all meet the discharge standards. The results could provide reference for coping with the impact of other loaded soybean products wastewater.

Abstract Platinum‐based alloy nanoparticles are the most attractive catalysts for the oxygen reduction reaction at present, but an in‐depth understanding of the relationship between their short‐range structural information and catalytic performance is still lacking. Herein, we present a synthetic strategy that uses transition‐metal oxide‐assisted thermal diffusion. PtCo/C catalysts with localized tetragonal distortion were obtained by controlling the thermal diffusion process of transition‐metal elements. This localized structural distortion induced a significant strain effect on the nanoparticle surface, which further shortened the length of the Pt–Pt bond, improved the electronic state of the Pt surface, and enhanced the performance of the catalyst. PtCo/C catalysts with special short‐range structures achieved excellent mass activity (2.27 A mgPt−1) and specific activity (3.34 A cm−2). In addition, the localized tetragonal distortion‐induced surface compression of the Pt skin improved the stability of the catalyst. The mass activity decreased by only 13% after 30,000 cycles. Enhanced catalyst activity and excellent durability have also been demonstrated in the proton exchange membrane fuel cell configuration. This study provides valuable insights into the development of advanced Pt‐based nanocatalysts and paves the way for reducing noble‐metal loading and increasing the catalytic activity and catalyst stability.

With the advancement of automobile lightweight, hot-dip galvanized low alloy high-strength steel strips are widely used in automobile structural parts or reinforcement due to their high yield strength and good forming, welding and anti-corrosion properties. Based on the research and development of hot-dip galvanized HC420LAD+Z steel strip in a steel plant, a low-cost and high-quality hot-dip galvanized HC420LAD+Z steel strip for automobile was developed from the aspects of process route design, reasonable control of chemical composition and optimization of key production process. The strip possessed good mechanical properties and adhesion to zinc layer, with the yield strength of 432~484 MPa, the tensile strength of 541~588 MPa, and the elongation A80 of 20.5~26.0%. Furthermore, the strip had batch stable production capacity, which provided a good reference for the industrial production of automotive high-strength steel.

The status of axillary lymph nodes is important for the staging, treatment, and prognosis of breast cancer. The arrival of the era of precision medicine highlights the importance of axillary lymph nodes status assessment. Magnetic resonance imaging, positron emission tomography/computed tomography, and new imaging examinations can be used in the assessment of axillary lymph nodes, in addition to routine examinations, such as physical examination and breast ultrasound. Sentinel lymph node biopsy is the most significant method for the assessment of axillary lymph nodes. Emerging evidence suggests that axillary lymph node dissection can be avoided in patients with negative or 1–2 positive sentinel lymph nodes. The ratio of inflammatory indicators may be a reliable predictor of lymph node metastases. Specific elder patients can have a good prognosis without axillary procedure. In this paper, we review and summarize the controversies surrounding the assessment methods and management of axillary lymph nodes. We hope to provide new perspectives for the axillary lymph node diagnosis and management of breast cancer patients under the concept of precision therapy.

Objective To explore the application of FOCUS-PDCA nursing mode in intensive medical observation points for COVID-19 close contacts and the effect of preventing and controlling epidemic situation. Methods FOCUS-PDCA nursing work mode was used to analyze the risk of infection among nurses. Combined with modern artificial intelligence technology, the implementation process of PDCA cycle was replaced with the "non-contact" implementation process. Results The centralized medical observation point operated for 25 days, and a total of 24 close contacts were treated. The nursing work was carried out successfully without infection, and the nursing quality was continuously improved. Conclusion The “non-contact” nursing practise based on FOCUS-PDCA mode can produce certain satisfactory effects. (目的 探讨FOCUS-PDCA护理工作模式在新型冠状病毒肺炎密切接触者集中医学观察点的应用及防控疫情的效果。方法 采用FOCUS-PDCA护理工作模式分析护理人员感染的风险问题, 与现代人工智能技术相结合, 将PDCA循环的实施过程改进为“无接触式”实施过程。结果 集中医学观察点运行25 d, 共收治24例密切接触者, 护理工作顺利开展, 无感染事件发生, 持续提高护理质量。结论 采用基于FOCUS-PDCA 的“无接触”护理工作模式, 效果较好, 值得借鉴。)

ObjectivesThis paper aims to study the fatigue damage problem of large ship prone to springing effect.MethodsThe test result in two generation 400 000 DWT very large ore carrier (VLOC) are compared based on ship model test method, and the relation of sea states and fatigue including hull girder springing are analyzed. According to the recursion method, a classical sea state is selected from a series of model test sea states.ResultsThe results show that the fatigue damage magnification effect has a trend relationship with significant wave height and encounter period. The concept of "dominant sea state" is proposed based on the recurrence method, and the expression of fatigue damage magnification factor is improved. The springing effect varies significantly according to different sea states, and the fatigue damage magnification effect of springing increases very rapidly as significant wave height and encounter period decrease.ConclusionsReplacing multiple model test loading conditions with dominant sea state could allow relatively accurate fatigue damage magnification factor to be ascertained rapidly. As such, this paper can provide references during the initial design period.

Proton exchange membrane fuel cells (PEMFCs) as energy conversion devices for hydrogen energy are crucial for achieving an eco-friendly society, but their cost and performance are still not satisfactory for large-scale commercialization. Multiple physical and chemical coupling processes occur simultaneously at different scales in PEMFCs. Hence, previous studies only focused on the optimization of different components in such a complex system separately. In addition, the traditional trial-and-error method is very inefficient for achieving the performance breakthrough goal. Machine learning (ML) is a tool from the data science field. Trained based on datasets built from experimental records or theoretical simulation models, ML models can mine patterns that are difficult to draw intuitively. ML models can greatly reduce the cost of experimental attempts by predicting the target output. Serving as surrogate models, the ML approach could also greatly reduce the computational cost of numerical simulations such as first-principle or multiphysics simulations. Related reports are currently trending, and ML has been proven able to speed up tasks in this field, such as predicting active electrocatalysts, optimizing membrane electrode assembly (MEA), designing efficient flow channels, and providing stack operation strategies. Therefore, this paper reviews the applications and contributions of ML aiming at optimizing PEMFC performance regarding its potential to bring a research paradigm revolution. In addition to introducing and summarizing information for newcomers who are interested in this emerging cross-cutting field, we also look forward to and propose several directions for future development.

Motivated by the relatively infrequent but very large price spikes in the day-ahead and real-time energy markets operated by the Electric Reliability Council of Texas, this paper proposes an insurance that a small and risk-averse retailer in Texas (i.e., a retail electric provider (REP)) may buy to prevent financial insolvency caused by inadequate risk management. It also demonstrates the insurance’s practical design, pricing, and implementation. As participation in the REP’s procurement auction is voluntary, the insurance is mutually beneficial for the REP and the insurance seller. Hence, the proposed insurance is a newly developed wholesale market product that deserves consideration by REPs in Texas and competitive retailers elsewhere.

Objective To discuss the feasibility of total endoscopic thyroidectomy on papillary thyroid microcarcinoma (PTMC) on the basis of the summary of benign thyroid diseases. Methods We summarized and analyzed the feasibility and experience of total endoscopic thyroidectomy of PTMC based on the retrospective analysis of the clinical data of 60 patients with benign thyroid diseases and 14 PTMC patients underwent total endoscopic surgery. Results In regard to the endoscopic thyroidectomy of benign thyroid diseases, the average size of the nodules was (2.79±0.66) cm and the average operation time was (162.77±32.39) min. As for the 14 cases of endoscopic thyroidectomy of PTMC, all patients undergone unilateral lobe with isthmus resection and ipsilateral lymph node dissection in the central region. The average size of the nodules was (0.65±0.26) cm and the average operation time was (200.77±24.37) min. The number of dissected central lymph nodes was (5.73±2.86). The median amount of intraoperative bleeding was 17ml. Unilateral lobe in 14 cases were completely removed. Among them, four cases occurred postoperative transient asymptomatic hypocalcemia, and no hoarseness. Conclusion Based on the experience of total endoscopic thyroidectomy of benign thyroid disease, it is safe and feasible to select PTMC for endoscopic surgery. Auxiliary techniques, such as carbon nanoparticles, neural monitoring, etc., could be used to fully expose the vision and improve the safety of operation.

A novel methodology to model electricity prices and latent causes as endogenous, multivariate time-series is developed and is applied to the Texas energy market. In addition to exogenous factors like the type of renewable energy and system load, observed prices are also influenced by some combination of latent causes. For instance, prices may be affected by power outages, erroneous short-term weather forecasts, unanticipated transmission bottlenecks, etc. Before disappearing, these hidden, unobserved factors are usually present for a contiguous period of time, thereby affecting prices. Using our system-wide latent factor model, we find that: (a) latent causes have a highly significant impact on prices in Texas; (b) the estimated latent factor series strongly and positively correlates to system-wide prices during peak and off-peak hours; (c) the merit-order effect of wind significantly dampens prices, regardless of region and time of day; and (d) the nuclear baseload generation also significantly lowers prices during a 24-h period in the entire system.

Three groups of SBR reactors A, B and C with different aeration time were set up to culture the activated sludge which has already bulked. The results showed that the settling performance of activated sludge in reactor A changed a little, but reactors B and C had been significantly improved. High-throughput sequencing results showed that the aeration time had a significant inhibitory effect on the growth of Thothrix, and the longer the aeration time was, the more obvious the inhibition was. When the aeration time is more than 6h, the SBR mode can effectively inhibit filamentous sludge bulking, and the longer the aeration time, the better the effect.

Abstract Background Cyclooxygenase-2(COX-2) promotes carcinogenesis, tumor proliferation, angiogenesis, prevention of apoptosis, and immunosuppression. Meanwhile, COX-2 over-expression has been associated with tumor behavior and prognosis in several cancers. This study investigated the antitumor effects of the selective COX-2 inhibitor, Celecoxib, on breast cancer in vitro and in vivo. Methods Human breast cancer MCF-7 and MDA-MB-231 cells were cultured with different concentration (10, 20, 40 μmol/L) of celecoxib after 0-96 hours in vitro. MTT assay was used to determine the growth inhibition of breast cancer cells in vitro. The expression of COX-2 on mRNA was measured by real-time quantitive PCR analysis. Flow cytometry was performed to analyze the cell cycle of MCF-7 cells. Levels of PGE2 were measured by ELISA method. The in vivo therapeutic effects of celecoxib were determined using rat breast cancer chemically induced by 7,12-dimethylben anthracene (DMBA). Results The inhibition of proliferation of both MCF-7 and MDA-MB-231 cells in vitro by celecoxib was observerd in time and dose dependent manner. Celecoxib effectively down-regulated the expression of COX-2. The cell cycle was arrested at G0/G1, and rate of cells in S phase was obviously decreased. Levels of PGE2 were inhibited by Celecoxib. The tumor incidence rate of the celecoxib group was lower than that of the control group. In addition, the tumor latency period of the celecoxib group was longer than that of the control group. Conclusions Celecoxib inhibited the proliferation of breast cancer cell lines in vitro, and prevented the occurrence of rat breast cancer chemically induced by DMBA. Therefore, celecoxib exhibits an antitumor activity and seems to be effective in anti-tumor therapy.

Abstract Background Diffusion-weighted (DW) imaging has shown potential to differentiate between malignant and benign breast lesions. However, different b values have been used with varied sensitivity and specificity. This study aims to prospectively evaluate the influence of b value on the detection and assessment of breast lesions. Methods Institutional review board approval and informed patient consent were obtained. Between February 2010 and September 2010, sixty women suspected of having breast cancer by clinical examination and mammography underwent bilateral breast MRI and DW imaging (with maximum b values of 600, 800, and 1000 s/mm2). Conspicuity grades of lesions at different b values on DW images were performed. Signal intensity and apparent diffusion coefficient (ADC) values were recorded and compared among different b values by the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and receiver operating characteristic (ROC) curve. Results Fifty-seven lesions from 52 recruited patients including 39/57 (68%) malignant and 18/57 (32%) benign were confirmed with pathology. DCE MRI accurately detected 53 lesions with the sensitivity of 93.0% and specificity of 66.7%, and DW imaging accurately detected 51 lesions with the sensitivity of 89.5% and specificity of 100%. There were no significant differences in conspicuity grades compared among the three b values (P = 0.072), although the SNR and CNR of breast lesions decreased significantly with higher b values. Mean ADCs of malignant lesions (b = 600 s/mm2, 1.07 ± 0.26 × 10-3 mm2/s; b = 800 s/mm2, 0.96 ± 0.22 × 10-3 mm2/s; b = 1000 s/mm2, 0.92 ± 0.26 × 10-3 mm2/s) were significantly lower than those of benign lesions (b = 600 s/mm2, 1.55 ± 0.40 × 10-3 mm2/s; b = 800 s/mm2, 1.43 ± 0.38 × 10-3 mm2/s; b = 1000 s/mm2, 1.49 ± 0.38 × 10-3 mm2/s) with all P values P = 0.303 and 0.840 for malignant and benign lesions, respectively). According to the area under the ROC curves, which were derived from ADC and differentiate malignant from benign lesions, no significant differences were found among the three b values (P = 0.743). Conclusions DW imaging is a potential adjunct to conventional MRI in the differentiation between malignant and benign breast lesions. Varying the maximum b value from 600 to 1000 s/mm2 does not influence the conspicuity of breast lesions on DW imaging at 1.5 T.

Abstract Background The exact mechanism of the effects of hypoxia on the proliferation and apoptosis in carcinoma cells is still conflicting. This study investigated the variation of hypoxia-inducible factor-1α(HIF-1α) expression and the apoptosis effect of hypoxia stimulated by cobalt chloride (CoCl2) in pancreatic cancer PC-2 cells. Methods PC-2 cells were cultured with different concentration (50-200 μmol/L) of CoCl2 after 24-120 hours to simulate hypoxia in vitro. The proliferation of PC-2 cells was examined by MTT assay. The cellular morphology of PC-2 cells were observed by light inverted microscope and transmission electron microscope(EM). The expression of HIF-1α on mRNA and protein level was measured by semi-quantitive RT-PCR and Western blot analysis. Apoptosis of PC-2 cells were demonstrated by flow cytometry with Annexin V-FITC/PI double staining. Results MTT assay showed that the proliferation of PC-2 cells were stimulated in the first 72 h, while after treated over 72 h, a dose- dependent inhibition of cell growth could be observed. By using transmission electron microscope, swollen chondrosomes, accumulated chromatin under the nuclear membrane and apoptosis bodies were observed. Flow cytometer(FCM) analysis showed the apoptosis rate was correlated with the dosage of CoCl2. RT-PCR and Western blot analysis indicated that hypoxia could up-regulate the expression of HIF-1α on both mRNA and protein levels. Conclusion Hypoxic microenvironment stimulated by CoCl2 could effectively induce apoptosis and influence cell proliferation in PC-2 cells, the mechanism could be related to up-expression of HIF-1α.

The study proposed a method for determining total nitrogen (TN) content in activated sludge by ultrasound pre-treatment assisted wet method. Based on the single-factor experiment, with the TN content as the response value, the response surface methodology was employed to examine the individual and interactive effects of three factors: the dilution multiple of the sludge mixture, ultrasonic time, and ultrasonic power. At the same time, the physico-chemical parameters and the digestion–oxidation parameters were optimised. The results indicated that the optimal parameters were as follows; sludge dilution multiple of 225 times, stirring rate of 400 r/min, ultrasonic time of 22 minutes, ultrasonic power of 720 W, and optimal added volume of potassium persulfate at 8 mL with a digestion time of 40 minutes. The relative standard deviation (RSD) for the parallel determination of TN in sludge samples using ultrasonic pre-treatment assisted wet method was ≤2.77%, with a spike recovery rate of 98.49–101.43%. The method, ultrasonic pre-treatment assisted wet method to determine TN concentration in activated sludge, was simpler to operate, more accurate. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g‐C3N4) assisted photocatalytic production of hydrogen peroxide (H2O2 has already attracted the interest of many researchers due to its environmental sustainability. Nevertheless, the inherent drawbacks of g‐C3N4 limit its progress. Metal‐free modification strategies, including nanostructure design, defect introduction, doping, and heterojunction construction, have been developed to improve the efficiency of g‐C3N4 photocatalytic H2O2 production. Compared to metal modification, metal‐free strategies avoid the use of precious metals and the leaching of heavy metal ions, which have the advantages of good stability and environmental friendliness. However, a comprehensive review of H2O2 production from g‐C3N4 modified by metal‐free strategies is still lacking. This review first recaps the mechanism of photocatalytic H2O2 production by g‐C3N4, including photoexcitation, carrier separation and redox reactions. Then, the perspective advances in metal‐free modified g‐C3N4 photocatalysts are presented, with the special focus on the kernel connection between different strategies and mechanism based on the pivotal stages of H2O2 production. Subsequently, recent applications of g‐C3N4‐based photocatalysts for in situ generated H2O2, mainly including water purification and organic synthesis, are briefly discussed. Finally, the prospects of g‐C3N4‐based photocatalysts are envisioned with the hope that it will have "something to do" in the field of H2O2 production. [ABSTRACT FROM AUTHOR]

The single-cycle transient high-concentration organic load shock test was conducted on the micropressure swirl reactor (MPSR) and sequencing batch reactor (SBR) to assess their capability to different levels of transient organic load shock (OLS), including pollutant removal, sludge characteristics, and microbial characteristics. The results indicated that the impact-resistance of biological treatment systems was related to reactor structure and microbial community distribution. When subjected to transient chemical oxygen demand (COD) load of 0.81, 1.28, and 1.70 g / (L · d a y) , respectively, both reactors exhibited effective organic removal capabilities. Compared with MPSR, within a certain shock range, nitrification in the SBR was less affected by shock and had a higher effect on nitrogen and phosphorus removal. However, when shock load reached 1.70 gCOD/(L·day) , the denitrification was sufficient in the MPSR, and microorganisms continued to secrete polysaccharides (PS), which was beneficial for adsorbing pollutants and resisting impacts. Under steady-state conditions, the SBR exhibited excellent nitrification with a relative abundance of 60.7% for nitrifying functional groups such as Thiothrix. Compared with the SBR, the MPSR displayed a higher microbial community diversity, with a variety of phosphorus-removing bacteria and denitrifying bacteria genera occupying aerobic and anoxic partitions within the same space, which was profitable for effective denitrification and phosphorus removal under high OLS. Besides, the enrichment of Flavobacterium and Zoogloea sp. at high concentrations significantly enhanced the MPSR's resistance to OLS. This study provides a theoretical basis for effective measures by different processes in response to organic load shocks. [ABSTRACT FROM AUTHOR]