Research on the Relative Placement Angle of the Induction Heater and the Channel in a Four-Channel Induction-Heating Tundish.

In order to optimize the application effect of induction heating (IH) tundishes, a four-channel IH tundish is taken as the research object. Based on numerical simulation methods, the influence of different relative placement angles of induction heaters and channels on the electromagnetic field, flow field and temperature field of the tundish is investigated. We focus on comparing the magnetic flux density (B) and electromagnetic force (EMF) distribution of the channel. The results show that regardless of the relative placement angle between the heater and the channel, the distribution of B in the central circular cross-section of the channel is eccentric. When the heater rotates around channel 1 towards the bottom of the tundish, the distribution of B in the central circular cross-section of the channel changes from a horizontal eccentricity to a vertical one. Through the analysis of the B contour in the longitudinal section of the channel, the difference in effective magnetic flux density area (ΔAB) between the upper and lower parts of the channel can be obtained, thereby quantitatively analyzing the distribution of B in this section. The distribution pattern of ΔAB is consistent with the distribution pattern of the electromagnetic force in the vertical direction (FZ) of the channel centerline. The ΔAB and FZ of channel 1 gradually increase as the heater rotates downwards, while those of channel 2 reach their maximum value at a rotation angle of 60°. Compared to the conventional placement, when the heater rotation angle is 60°, the outlet flow velocities at channel 1 and channel 2 decrease by 15% and 12%, respectively. However, the outlet temperature at channel 2 increases by 1.96 K, and the molten steel flow at the outlet of channel 1 and channel 2 no longer exhibits significant downward flow. This shows that when the heater rotation angle is 60°, it has a dual advantage. On the one hand, it is helpful to reduce the erosion of the molten steel on the channel and the bottom of the discharging chamber, and on the other hand, it can more effectively exert the heating effect of the induction heater on the molten steel in the channel. This presents a new approach to enhance the application effectiveness of IH tundish.

Evaluation of pancreatic iodine uptake and related influential factors in multiphase dual-energy CT.

OBJECTIVES: To establish normative values and identify potential factors influencing pancreatic iodine uptake using dual-energy CT (DECT). MATERIALS AND METHODS: This retrospective study included participants without pancreatic diseases undergoing DECT at two institutions with different platforms. Their protocols both included arterial phase (AP), portal venous phase (PP), and equilibrium phase (EP), defined as 35 s-40 s, 60 s-70 s, and 150 s-180 s after injection of contrast agent, respectively. Both iodine concentration (IC) and normalised IC (NIC) were measured. Demographic features, local measurements of the pancreas and visceral fat area (VFA) were considered as potential factors influencing iodine uptake using multivariate linear regression analyses. RESULTS: A total of 562 participants (median age 58 years [interquartile range: 47-67], with 282 men) were evaluated. The mean IC differed significantly between two institutions (all p < 0.001) across three contrast-enhanced phases, while the mean NIC showed no significant differences (all p > 0.05). The mean values of NIC were 0.22 at AP, 0.43 at PP and 0.45 at EP. NICAP was independently affected by VFA (ß = 0.362, p < 0.001), smoking (ß = -0.240, p = 0.001), and type-II diabetes (ß = -0.449, p < 0.001); NICPP by VFA (ß = -0.301, p = 0.017) and smoking (ß = -0.291, p < 0.001); and NICEP by smoking (ß = -0.154, p = 0.10) and alcohol consumption (ß = -0.350, p < 0.001) with statistical power values over 0.81. CONCLUSION: NIC values were consistent across institutions. Abdominal obesity, smoking, alcohol consumption, and diabetes are independent factors influencing pancreatic iodine uptake. CLINICAL RELEVANCE STATEMENT: This study has provided reference normative values, influential factors and effective normalisation methods of pancreatic iodine uptake in multiphase dual-energy CT for future studies in this area as a new biological marker. KEY POINTS: Evaluation of pancreatic iodine uptake measured by dual-energy CT is a promising method for future studies. Abdominal obesity, smoking, alcohol consumption, diabetes, and sex are independent factors influencing pancreatic iodine uptake. Utility of normalised iodine concentration is necessary to ensure the consistency across different institutions.

A comprehensive metabolomics analysis of volatile and non-volatile compounds in matcha processed from different tea varieties.

Tea varieties play a crucial role on the quality formation of matcha. This research aimed to examine the impact of four specific tea plant varieties (Okumidori, Longjing 43, Zhongcha108, and E'Cha 1) on various aspects of matcha, including sensory evaluation, major components, color quality, volatile and non-volatile metabolomic profiles. The findings revealed that the levels of tea polyphenols, ester catechins, nonester catechins, and amino acids varied among these four varieties. Notably, 177 significant different metabolites, such as phenolic acids, flavonoids, tannins, alkaloids were identified among 1383 non-volatile compounds. In addition, 97 key aroma-active compounds were identified based on their odor activity value exceeding 1. Aldehydes, heterocyclic compounds, and ketones were closely associated with the formation of volatile metabolites. Overall, this study enhances our understanding of how different tea plant varieties impact the quality of matcha, and can provide valuable guidance for improving matcha varieties in a favorable direction.

Non-Targeted Metabolomics Reveals the Effects of Different Rolling Methods on Black Tea Quality.

A non-targeted metabolomics approach and sensory evaluation, coupled with multivariate statistical analysis, systematically uncover the impact of the rolling time on the quality parameters of black tea. GC-MS analysis reveals that a moderate extension of rolling time favorably contributes to the accumulation of characteristic aroma components in black tea. The volatile components reach their highest concentration in black tea samples processed during an 80-min rolling period. UHPLC-Q-TOF/MS analysis demonstrates a substantial decrease in the contents of catechins and flavonoids with an increase in rolling time. Simultaneously, the production of theaflavins, coupled with the degradation of green bitterness volatiles (GBVs), significantly contributes to the formation of endogenous aroma components in black tea. These findings underscore the close relationship between rolling time control and black tea quality, emphasizing that a moderate extension of the rolling time fosters the development of improved black tea flavor quality. The comprehensive quality evaluation indicates that the optimal duration is 80 min. However, the initial 0 to 20 min of rolling is a crucial phase for the genesis and transformation of black tea quality. This study offers valuable insights into the influence of rolling time on black tea quality, potentially enhancing future studies of rolling technology. It provides theoretical guidelines for optimizing the processing of Gongfu black tea.

Aging pattern of the brainstem based on volumetric measurement and optimized surface shape analysis.

The brainstem, a small and crucial structure, is connected to the cerebrum, spinal cord, and cerebellum, playing a vital role in regulating autonomic functions, transmitting motor and sensory information, and modulating cognitive processes, emotions, and consciousness. While previous research has indicated that changes in brainstem anatomy can serve as a biomarker for aging and neurodegenerative diseases, the structural changes that occur in the brainstem during normal aging remain unclear. This study aimed to examine the age- and sex-related differences in the global and local structural measures of the brainstem in 187 healthy adults (ranging in age from 18 to 70 years) using structural magnetic resonance imaging. The findings showed a significant negative age effect on the volume of the two major components of the brainstem: the medulla oblongata and midbrain. The shape analysis revealed that atrophy primarily occurs in specific structures, such as the pyramid, cerebral peduncle, superior and inferior colliculi. Surface area and shape analysis showed a trend of flattening in the aging brainstem. There were no significant differences between the sexes or sex-by-age interactions in brainstem structural measures. These findings provide a systematic description of age associations with brainstem structures in healthy adults and may provide a reference for future research on brain aging and neurodegenerative diseases.

The Role of KDM2A and H3K36me2 Demethylation in Modulating MAPK Signaling During Neurodevelopment.

Intellectual disability (ID) is a condition characterized by cognitive impairment and difficulties in adaptive functioning. In our research, we identified two de novo mutations (c.955C>T and c.732C>A) at the KDM2A locus in individuals with varying degrees of ID. In addition, by using the Gene4Denovo database, we discovered five additional cases of de novo mutations in KDM2A. The mutations we identified significantly decreased the expression of the KDM2A protein. To investigate the role of KDM2A in neural development, we used both 2D neural stem cell models and 3D cerebral organoids. Our findings demonstrated that the reduced expression of KDM2A impairs the proliferation of neural progenitor cells (NPCs), increases apoptosis, induces premature neuronal differentiation, and affects synapse maturation. Through ChIP-Seq analysis, we found that KDM2A exhibited binding to the transcription start site regions of genes involved in neurogenesis. In addition, the knockdown of KDM2A hindered H3K36me2 binding to the downstream regulatory elements of genes. By integrating ChIP-Seq and RNA-Seq data, we made a significant discovery of the core genes' remarkable enrichment in the MAPK signaling pathway. Importantly, this enrichment was specifically linked to the p38 MAPK pathway. Furthermore, disease enrichment analysis linked the differentially-expressed genes identified from RNA-Seq of NPCs and cerebral organoids to neurodevelopmental disorders such as ID, autism spectrum disorder, and schizophrenia. Overall, our findings suggest that KDM2A plays a crucial role in regulating the H3K36me2 modification of downstream genes, thereby modulating the MAPK signaling pathway and potentially impacting early brain development.

Case report: Episodic psychosis caused by a novel SCP2 splicing mutation.

SCPx deficiency is a rare disorder of peroxisomal beta-oxidation dysfunction, and it has only been documented in two patients thus far. In the previously reported patients, both patients were primarily presented with slowly progressive dystonia or ataxia, and they both displayed symmetrical lesions in the thalamus and brainstem on magnetic resonance imaging. This study presents the third patient exhibiting a similar neuroimaging abnormality but a notably different clinical phenotype characterized by episodic psychosis. Through whole-exome sequencing, we identified a homozygous splicing mutation in SCP2 (c.674 + 1G > C), and further RNA sequencing revealed exon 8 skipping in the mature transcripts of SCP2. This study significantly expands our understanding of the genotypic and phenotypic spectrum associated with SCP2-related metabolic encephalopathy.

The metabolic score for insulin resistance as a predictor of clinical outcome in stroke patients treated by intravenous thrombolysis.

BACKGROUND AND PURPOSE: Insulin resistance is associated with clinical outcomes among patients with ischemic stroke. We aimed to investigate the association between metabolic score for insulin resistance (METS-IR) and clinical outcomes in stroke patients treated by intravenous thrombolysis (IVT). METHODS: We recruited participants treated with IVT from a prospective registry including 3 stroke centers. Poor outcome was defined as a modified Rankin scale score ≥ 3 points at 90 days after the index stroke. We performed logistic regression models to investigate the association between METS-IR and the risk of poor outcome. We used the receiver operative characteristic to assess the discriminative ability and the restricted cubic spline to explore the relationship between METS-IR and the poor outcome. RESULTS: This study enrolled a total of 1074 patients (median age, 68; 63.8% male). Three hundred sixty (33.5%) patients had poor outcome after IVT. METS-IR was associated with the risk of the poor outcome with the increase of confounding factors in models (odds ratio [OR], 1.078; 95% confidence interval [CI], 1.058-1.099; P < 0.001). The area under the curve for METS-IR for predicting the poor outcome was 0.790 (95% CI, 0.761-0.819). The restricted cubic spline revealed an increasing and non-linear association between METS-IR and the poor outcome (P for non-linearity < 0.001). CONCLUSION: Our study found that METS-IR was associated with an increased risk of poor outcome after IVT. Further studies are warranted to investigate the efficacy of anti-diabetic agents regarding IR on clinical outcomes after IVT.

Dual-energy CT virtual non-calcium: an accurate method for detection of knee osteoarthritis-related edema-like marrow signal intensity.

OBJECTIVES: To evaluate the performance of a dual-energy computed tomography (DECT) virtual non-calcium (VNCa) technique in the detection of edema-like marrow signal intensity (ELMSI) in patients with knee joint osteoarthritis (OA) compared to magnetic resonance imaging (MRI). METHODS: The study received local ethics board approval, and written informed consent was obtained. DECT and MRI were used to examine 28 knees in 24 patients with OA. VNCa images were generated by dual-energy subtraction of calcium. The knee joint was divided into 15 regions for ELMSI grading, performed independently by two musculoskeletal radiologists, with MRI as the reference standard. We also analyzed CT numbers through receiver operating characteristics and calculated cut-off values. RESULTS: For the qualitative analysis, we obtained CT sensitivity (Readers 1, 2 = 83.7%, 89.8%), specificity (Readers 1, 2 = 99.5%, 99.5%), positive predictive value (Readers 1, 2 = 95.3%, 95.7%), and negative predictive value (Readers 1, 2 = 97.9%, 98.7%) for ELMSI. The interobserver agreement was excellent (κ = 0.92). The area under the curve for Reader 1 and Reader 2 was 0.961 (95% CI 0.93, 0.99) and 0.992 (95% CI 0.98, 1.00), respectively. CT numbers obtained from the VNCa images were significantly different between regions with and without ELMSI (p < .001). CONCLUSIONS: VNCa images have good diagnostic performance for the qualitative and quantitative analysis of knee osteoarthritis-related ELMSI.

IL-1ß knockdown inhibits cigarette smoke extract-induced inflammation and apoptosis in vascular smooth muscle cells.

OBJECTIVE: This study was aimed to investigate the role of interleukin-1ß (IL-1ß) in cigarette smoke extract (CSE)-induced apoptosis in vascular smooth muscle cells and the underlying mechanism in a rat derived cell line. METHODS: Rat thoracic aortic smooth muscle cells (A7r5) were divided into six groups including control, CSE (model), CSE+ overexpression empty vector (OvExp-EV), CSE+IL-1ß knockdown (KD), and CSE+ IL-1ß knockdown empty vector (KD-EV). The mRNA expression levels of IL-1ß and pregnancy-associated plasma protein A (PAPP-A) were detected by quantitative polymerase chain reaction (qPCR). The apoptosis of A7r5 cells was detected by flow cytometry. The expression levels of inflammatory mediators (TNFα, IL-6 and IL-8) and apoptotic proteins (Bax and Bcl-2) were determined by western blot. RESULTS: CSE induced significant apoptosis in vascular smooth muscle cells (P < 0.01) and elevated the mRNA levels of IL-1ß and PAPP-A (P < 0.01). CSE administration increased protein expression of Bax, TNF-α, IL-6, and IL-8, with significantly reduced Bcl-2 expression (P < 0.01). IL-1ß knockdown significantly decreased cell apoptosis via regulating the expression of these proteins (P < 0.05 or P < 0.01). CONCLUSION: IL-1ß is involved in CSE-induced PAPP-A expression and apoptosis in vascular smooth muscle cells, which might be considered as a target for preventing of cardiovascular diseases caused by cigarette smoking.

Modification of Inclusions by Rare Earth Elements in a High-Strength Oil Casing Steel for Improved Sulfur Resistance.

Steel casing pipes used in the construction of deep oil wells usually require both high strength and corrosion-resistant behavior. Due to the exploration of deep H2S-bearing oil reservoirs, sulfide stress cracking (SSC) is becoming an increasingly serious concern for casing steel. The nonmetallic inclusions in the steel are among the key reasons for its service failure. The rare earth element Ce can be used to modify the inclusions in casing steel and improve its SSC resistance. Here, taking C110 grade casing steel (the highest class currently in service) as the investigated object, the modification behavior of Ce inclusions in the steel and the effect of the addition of Ce in varying amounts (0.01, 0.024, and 0.042 wt.%) on the modified products were studied through high-temperature tube furnace experiments and thermodynamic calculations. The results showed that Ce had an obvious modification effect on the CaO·Al2O3 inclusions in casing steel, and the diffusion of dissolved Ce in the steel was the limiting step of the modification reaction. With the extension of reaction time, the sequence describing the modification of inclusions in the steel was determined as follows: CaO·Al2O3 → CeAlO3 → Ce2O3/Ce2O2S. The final stable product after modification depended on the amount of Ce added. With 0.01 wt.% Ce, the stable phase in molten steel was Ce2O3; on the other hand, upon adding ≥0.024 wt.% Ce, the stable phase became Ce2O2S. In addition, the thermodynamic stability of Ce2O3 decreased, and it was transformed into CeAlO3, Ce2O2S, Ce2S3, and CeS during solidification. On the basis of our results and the considerations for smooth casting, the addition of a proper amount of a rare earth element is suggested for industrial trials, following the achievement of a significant and surprising improvement in the qualified rate of SSC resistance for the final steel products. The relevant mechanism is also analyzed.

Immobilization of by-product sulfate salt slag from high-salt organic wastewater with fly ash in lightweight aggregate ceramsite.

The lightweight aggregate ceramsite (LAC) was prepared from by-product sulfate salt slag (BPSS) of high-salt organic wastewater with fly ash. The BPSS fixation rate, leaching toxicity, morphological structures and potential environmental risks of heavy metals in LAC were investigated. BPSS can be fixed in LAC when the mass ratio of Fly ash: Kaolin: clay was 7:1:2, the addition of BPSS was 28%, the heating rate was 8°C min-1, and the calcination temperature was 1100°C. The characteristics of the LAC met the requirements for Chinese lightweight aggregate standards (GB/T17431.2-2010). The Total Organic Carbon (TOC) content of the aqueous leaching liquor in LAC was less than 0.5 mg·L-1. And the fixation rate of heavy metal was more than 99%, which meets the requirements of GB 5085.3-2007. The BPSS immobilization mechanisms were mainly related to the formation of new crystal phases, including Leucite (KAlSi2O6), Albite (Na2O·Al2O3·6SiO2), Potash Feldspar (K2O·Al2O3·6SiO2), Jadeite (NaAlSi2O6), Hauyne ([Na,Ca]8[Si,Al]12O24[SO4]2), Nosean (Na8Al6Si6O24SO4), and Sodalite (Na8Al6Si6O24[MnO4]2) by incorporation of heavy metals in high-temperature curing reaction. This work provides an effective method for the harmless treatment and recycling of by-product salt residues from high-salt organic wastewater.

Age and Five-Year Outcomes After Carotid Artery Stenting in Symptomatic Carotid Stenosis: A Retrospective Cohort Study.

BACKGROUND: Several clinical trials have reported that periprocedural risk of carotid artery stenting (CAS) increase with age. China is experiencing one of the most rapid transitions to an aging society, while the clinical outcomes of CAS in real-world China are still limited. The study aimed to compare the periprocedural and an extending 5-year event rates between younger and older patients treated by CAS to testify the safety of CAS in older patients in China. METHODS: This is a single center, retrospective cohort study. Symptomatic patients who underwent CAS from Nov 2011 to June 2014 were retrospectively included in this study, The population was divided into two age groups: <70 and ≥70. The main primary endpoint was stroke, myocardial infarction or death occurring at 30 days, or ipsilateral stroke over 5-year after stenting. RESULTS: A total of 103 symptomatic patients (<70: 68%; ≥70: 32%) with CAS included in the study. During the 30-day period, the rate of primary outcome was 1.0% with only one stroke in patients younger than 70 years old (P = 1.000). After five years, the rate of primary outcome was low (10.9%, 10/92) despite some of the patients had major stroke or underwent bilateral C1 stenting. There was no significant difference in the 5-year rates of the primary outcome between the young and old groups (12.3% vs 7.4%, P = .718). Kaplan-Meier estimates of the proportion of study participants with a primary endpoint showed that there was no significant age-dependent difference of the stroke and death outcome in symptomatic patients. CONCLUSIONS: Age (<70 vs ≥ 70) had no influence on the risk of stroke or death in symptomatic patients either in the short or long term. CAS is an optimal treatment for older patients with cervical carotid artery stenosis, and CAS was safe for those with major stroke or bilateral C1 stenting.

Experiences of bowel symptoms in patients with rectal cancer after sphincter-preserving surgery: a qualitative meta-synthesis.

PURPOSE: This study is to identify and synthesize the available evidence of bowel symptom experiences of patients with rectal cancer after sphincter-preserving surgery (SPS). METHODS: This qualitative meta-synthesis was conducted following the Joanna Briggs Institute (JBI) qualitative systematic review methodology and reported following the Enhancing Transparency in Reporting the Synthesis of Qualitative Research (ENTREQ) guidelines. Seven databases were searched on 22 December 2021. The selected studies were reviewed by two independent reviewers, and disagreements were resolved by discussion or with a third reviewer. RESULTS: Seven qualitative articles were included in the meta-synthesis with 192 total rectal cancer patients. The review summarized 53 qualitative findings into three synthesized findings: (a) Patients experienced bowel symptoms and triggered additional physiological problems, and they underestimated bowel symptoms; (b) patients had many negative emotions, and their daily life and social interaction were disturbed; and (c) patients adopted strategies to adapt or control their bowel symptoms. According to the ConQual evidence grading approach, the confidence of the synthesized findings was rated as moderate to low. CONCLUSIONS: The bowel symptoms of patients with rectal cancer after SPS have troubled their lives. Timely acquisition of symptom-related knowledge and enhancement of their coping abilities are important for the control and management of bowel symptoms. Healthcare professionals should clearly understand the bowel symptoms that patients may experience after SPS and provide supportive care for patients to improve patients' self-management abilities and quality of life. TRIAL REGISTRATION: PROSPERO: CRD42021242610.

Influencing factors and mechanism of tourists' pro-environmental behavior - Empirical analysis of the CAC-MOA integration model.

Tourism has been perceived as an environmentally friendly industry for a long term, but the negative impact of tourist irresponsible behavior on the environment cannot be ignored. Tourists' pro-environmental behavior is crucial to the destination's sustainable development. Taking stimulus-organism-response theory as a framework, this study explores the factors and mechanisms influencing tourists' pro-environmental behaviors by integrating cognitive-affective-conative (CAC) theory and motivation-opportunity-ability (MOA) theory. Through the PLS-SEM analysis with 548 questionnaires, the driving mechanism of tourists' pro-environmental behavior was deeply explored. The results indicate that tourists' environmental knowledge, participation motivation, and opportunity have significant positive effects on pro-environmental behavior, but the role of participation ability on tourists' pro-environmental behavior is not confirmed. Tourists have significant environmental self-identity and environmental commitment, and these affections actively promote tourists' pro-environmental behavior. Except for the participation ability, the other three factors, respectively, influence tourists' environmental behavior through the mediating effects of environmental self-identity and environmental commitment. Given the limited literature integrating CAC and MOA theories within research on tourists' pro-environmental behavior, these findings provide new perspectives for future research. This research enriches the literature on the factors influencing tourist pro-environmental behavior and also provides practical guidance for promoting tourists' pro-environmental behavior.

Chemical component analysis of the traditional Chinese medicine Guipi Tang and its effects on major depressive disorder at molecular level.

Ethnopharmacological relevance: Guipi Tang (GPT) is a widely used traditional Chinese medicine that is used to treat major depressive disorder. However, the molecular mechanisms of its effects remain unclear. Aim of the study: This study aimed to investigate the antidepressant-like effects of GPT and explore its underlying molecular mechanisms. Materials and methods: Male Sprague-Dawley rats were subjected to a chronic unpredictable mild stress (CUMS) procedure and treated with various doses of GPT, with fluoxetine treatment as a positive control. Behavioural tests (including sucrose preference test, novelty-suppressed feeding test, open-field test and forced swim test), terminal deoxynucleotidyl transferase dUTP nick end labeling and enzyme-linked immunosorbent assay were conducted. The levels of Bax, Bcl-2, cleaved caspase-3, PI3K, p-PI3K, AKT, p-AKT, BDNF, TrkB and CREB or p-CREB were assessed at the protein level using western blotting or immunofluorescence. Results: GPT consists of mainly known drugs, such as liquiritin and ginsenosides. It reversed depressive behaviours and decreased cell apoptosis in the hippocampi of CUMS rats. It significantly upregulated the protein level of Bax, p-Akt, p-PI3K, BDNF, TrkB and p-CREB and downregulated the level of cleaved caspase-3 and Bcl-2. Conclusions: GPT had anti-depressive activity as indicated by the amelioration of depression-like behaviour and the inhibition of hippocampal neuronal apoptosis in CUMS rats. This inhibition was mediated partly by modulating the PI3K/Akt and/or BDNF/TrkB/CREB pathway, in which, glycosides, the main components of GPT, might be involved.

Remarkable performance of atomically dispersed cobalt catalyst for catalytic removal of indoor formaldehyde.

The single atom catalysts have been widely studied in the catalytic reaction due to their 100% atomic utilization and ultra-high catalytic activity. However, the catalytic removal of formaldehyde on single atom catalysts have not been studied extensively and its catalytic mechanism is still unclear. In this work, atomically dispersed Co catalysts anchored in porous nitrogen-doped carbon were synthetized and the coordination environment of single Co atoms were further proved by the results of XAFS spectrum. The optimal atomically dispersed Co catalysts preformed outstanding removal performance for low-concentration HCHO (∼1 ppm) at room temperature. Furthermore, DFT calculations reveal the HCHO removal mechanism on atomically dispersed Co catalysts, which showed that HCHO molecules can react with O2 molecules adsorbed on single-atom Co sites through the Langmuir-Hinshelwood (L-H) pathway to generate CO2 and H2O at room temperature (HCHO â†’ HCOO* → CO2). This work provides a promising lead for exploring single-atom Co catalysts for HCHO oxidation.

Effect of Flow Field Optimization of an Asymmetric Multi-Strand Tundish on the Quality Consistency of Cracking Con-Rod Steel.

Cracking con-rod is an advanced high-precision connecting structure based on brittle expansion, breaking and reconnection of steel, to solve the problem of assembly circle missing. High carbon micro-alloyed steel C70S6, as a dominant material for the production of cracking con-rod, has extremely strict requirements on non-metallic inclusions in steel and microstructure stability. Continuous casting tundish plays an important role in removing large-sized inclusions and stabilizing casting quality. Aiming at the inconsistent casting quality of C70S6 steel produced by a three-strand asymmetric tundish and the frequent occurrence of slag entrapment problems in Xining Special Steel, the tundish structure was optimized by means of physical modelling combined with numerical simulation, and the quality of the bloom castings and subsequent hot-rolled products before and after optimization were compared based on volume production. The results show that a new flow control design to the tundish can effectively improve the consistency of its metallurgical effect for each of the three strands and the following overall product quality, in which the flow field and temperature field in the tundish are more uniform. This is due to the adoption of a vortex inhibitor and an optimized wall structure according to the measured RTD curve, ink trajectory and numerical simulation on the 3-D streamline contours and temperature distribution in the tundish. The peak concentration of outlet 1 is decreased from 6.5 before optimization to less than 2.0 after optimization, which means the elimination or alleviation of the local short-circuit flow. The maximum temperature difference of C70S6 molten steel measured at the outlets of the tundish three strands is decreased from 2-5 °C to 1-3 °C, which is in good agreement with the numerical simulation results. The difference in columnar crystal ratio of the corresponding bloom castings is decreased from 2.27-3.17% to 1.26-1.85%, and the consistency of central carbon segregation index is also significantly improved. In addition, the difference in oxygen content among the three strand blooms is decreased from 1.7-3.5 ppm to 0.8-1.9 ppm. As a result, the overall mechanical properties and microstructure stability of the hot-rolled products are improved statistically, in which the hardness fluctuation is decreased from 84 HBW to 60 HBW, the inclusion grade of types B + C + D + Ds is reduced to 1.105, and the occurrence rate of Ds dropped to 0.118%. Accordingly, the failure rate of the cracking con-rod is controlled stably within 4‱, and the fracture is generally smoother than that before tundish optimization. In summary, the flow field optimization to a multi-strand asymmetric tundish has a clear effect on improving the overall quality of its bloom castings and rolled products, which should be paid more attention industrially. Meanwhile, the present study provides a reliable theoretical and experimental reference for the improvement of metallurgical effects of an asymmetric-typed tundish commonly used in special steel production.

Malnutrition and Risk of Mortality in Ischemic Stroke Patients Treated With Intravenous Thrombolysis.

Background and Purpose: Malnutrition is highly prevalent in ischemic stroke patients. We aimed to investigate whether malnutrition indexes may be useful in predicting mortality at 90 days in ischemic stroke patients treated with intravenous thrombolysis. Methods: We retrospectively analyzed consecutive patients who underwent thrombolytic therapy at three comprehensive stroke centers. Malnutrition was assessed using the controlling nutritional status (CONUT) score, geriatric nutritional risk index (GNRI), and prognostic nutritional index (PNI). Results: Of 979 patients (mean age, 66.8 years; males, 63.6%) included in this study, 91 (9.3%; 95% confidence interval [CI]: 8.4-10.2%) died at 3-month follow up. According to the CONUT, GNRI, and PNI scores, 9.9, 33.7, and 7.0% of patients were moderately or severely malnourished, respectively; 64.0% were at least mildly malnourished by at least 1 malnutrition index. In the multivariate regression model after adjusting for potential confounders, malnutrition (severe risk versus normal nutritional status) was significantly associated with an increased risk of mortality for CONUT scores (adjusted odds ratio [OR] 16.16, 95%CI, 7.86-67.11; P < 0.001), GNRI scores (adjusted OR 9.82, 4.10-23.51; P < 0.001) and PNI scores (adjusted OR 12.74, 5.56-29.19; P < 0.001). Similar results were found when the malnutrition scores were analyzed as continuous variables. Adding the three malnutrition indexes to models containing conventional risk factors significantly improved risk reclassification for 3-month mortality. Conclusion: Our study showed that malnutrition may be associated with a higher risk of mortality at 3 months in ischemic stroke after intravenous thrombolysis.