CT semi-quantitative score used as risk factor for hyponatremia in patients with COVID-19: a cross-sectional study.

Purpose: Chest computed tomography (CT) is used to determine the severity of COVID-19 pneumonia, and pneumonia is associated with hyponatremia. This study aims to explore the predictive value of the semi-quantitative CT visual score for hyponatremia in patients with COVID-19 to provide a reference for clinical practice. Methods: In this cross-sectional study, 343 patients with RT-PCR confirmed COVID-19, all patients underwent CT, and the severity of lung lesions was scored by radiologists using the semi-quantitative CT visual score. The risk factors of hyponatremia in COVID-19 patients were analyzed and combined with laboratory tests. The thyroid function changes caused by SARS-CoV-2 infection and their interaction with hyponatremia were also analyzed. Results: In patients with SARS-CoV-2 infection, the total severity score (TSS) of hyponatremia was higher [M(range), 3.5(2.5-5.5) vs 3.0(2.0-4.5) scores, P=0.001], implying that patients with hyponatremia had more severe lung lesions. The risk factors of hyponatremia in the multivariate regression model included age, vomiting, neutrophils, platelet, and total severity score. SARS-CoV-2 infection impacted thyroid function, and patients with hyponatremia showed a lower free triiodothyronine (3.1 ± 0.9 vs 3.7 ± 0.9, P=0.001) and thyroid stimulating hormone level [1.4(0.8-2.4) vs 2.2(1.2-3.4), P=0.038]. Conclusion: Semi-quantitative CT score can be used as a risk factor for hyponatremia in patients with COVID-19. There is a weak positive correlation between serum sodium and free triiodothyronine in patients with SARS-CoV-2 infection.

Resveratrol Alleviates Liver Fibrosis Induced by Long-Term Inorganic Mercury Exposure through Activating the Sirt1/PGC-1α Signaling Pathway.

Liver disease has become an important risk factor for global health. Resveratrol (Res) is a natural polyphenol which is widely found in foods and has a variety of biological activities. This study investigated the role of the microbiota-gut-liver axis in the Res relieving the liver fibrosis induced by inorganic mercury exposure. Twenty-eight mice were divided into four groups (n = 7) and treated with mercuric chloride and/or Res for 24 weeks, respectively. The results showed that Res mitigated the ileum injury induced by inorganic mercury and restrained LPS and alcohol entering the body circulation. Network pharmacological and molecular analyses showed that Res alleviated oxidative stress, metabolism disorders, inflammation, and hepatic stellate cell activation in the liver. In conclusion, Res alleviates liver fibrosis induced by inorganic mercury via activating the Sirt1/PGC-1α signaling pathway and regulating the microbial-gut-liver axis, particularly, increasing the relative enrichment of Bifidobacterium in the intestinal tract.

Epidemiological and clinical characteristics of burns in adults: a 6-year retrospective study in a major burn center in Suzhou, China.

Background: Burns are a prevalent form of unintentional injury and a significant public health concern in developing countries. We aimed to investigate the epidemiological and clinical characteristics of adult burn patients at a major center in Eastern China. Methods: This 6-year retrospective study analyzed patients with varying degrees of burns between January 2017 and December 2022 at the Suzhou Burns and Trauma Center. The study extracted demographic, clinical, and epidemiological data from electronic medical records for analysis. Results: The study included 3,258 adult patients, of which 64.3% were male. The largest age group affected 30-59-year-old adults (63.04%). Scalds were the leading cause of burns (1,346, 41.31%), followed by flames (1,271, 39.01%). The majority of burn hospitalizations were those with moderate burns (1791, 54.97%). The morbidity rate was low at 0.68%, while mortality was strongly associated with age, etiology, and total body surface area. Patients with certain types of burns, such as explosions, hot crush injuries, and electric burns had more operations, longer lengths of hospital stay, and higher costs compared to those with scalds and flame injuries. Conclusion: Different prevention strategies should be formulated according to different etiologies, ages, and genders.

Study on displacement units for water flooded low-permeability oil reservoirs.

Understanding the reservoir feature changes is essential for optimizing oil exploitation throughout the development lifecycle. This paper proposed an analytical displacement unit method to character the features of water-flooded, low-permeability oil reservoirs. The method hinges the ratio of fluid flux to area and average water saturation, providing a fine description of reservoir dynamics. It has been implemented in a case study of a five-spot waterflooding scheme. The reservoir can be categorized into sixteen distinct unit types, each with specific attributes. This paper delves into the evolution of these displacement units and the key factors that influence their behavior. The findings provide insights into the degree of waterflooding and oil distribution following continuous waterflooding. Furthermore, the proposed method offers a valuable framework for analyzing the development of dominant water flow channels and exploiting the residual oil.

Genetic variants in UNC93B1 predispose to childhood-onset systemic lupus erythematosus.

Rare genetic variants in toll-like receptor 7 (TLR7) are known to cause lupus in humans and mice. UNC93B1 is a transmembrane protein that regulates TLR7 localization into endosomes. In the present study, we identify two new variants in UNC93B1 (T314A, located proximally to the TLR7 transmembrane domain, and V117L) in a cohort of east Asian patients with childhood-onset systemic lupus erythematosus. The V117L variant was associated with increased expression of type I interferons and NF-κB-dependent cytokines in patient plasma and immortalized B cells. THP-1 cells expressing the variant UNC93B1 alleles exhibited exaggerated responses to stimulation of TLR7/-8, but not TLR3 or TLR9, which could be inhibited by targeting the downstream signaling molecules, IRAK1/-4. Heterozygous mice expressing the orthologous Unc93b1V117L variant developed a spontaneous lupus-like disease that was more severe in homozygotes and again hyperresponsive to TLR7 stimulation. Together, this work formally identifies genetic variants in UNC93B1 that can predispose to childhood-onset systemic lupus erythematosus.

Visceral Fat Area and Subcutaneous Fat Area Increase in Hyperthyroidism Patients After Treatment-A Single-Group Repeated-Measures Trial.

Purpose: There is evidence that long-term vascular risk remains increased in patients with hyperthyroidism even after normalization of thyroid function, and the mechanisms that regulate this risk are unclear. The aim of this study was to assess how visceral fat area and subcutaneous fat area change after hyperthyroidism treatment, and to further explore the relationship between thyroid hormones, abdominal fat area (visceral fat area and subcutaneous fat area), and lipids. Patients and Methods: 50 patients with newly diagnosed Graves' disease were selected. Anthropometric parameters (weight, height, body mass index, waist circumference, neck circumference), laboratory parameters (thyroid hormones, lipid metabolism indices), abdominal fat area (visceral fat area and subcutaneous fat area), and drug dose were collected. Measurements were made at baseline, 6 and 12 months after treatment. We used linear mixed-effects models for analysis. Results: The results showed that the following indexes changed significantly at different time points: visceral fat area, subcutaneous fat area, free triiodothyronine, free thyroxine, thyroid stimulating hormone, total cholesterol, high-density lipoprotein, low-density lipoprotein, body weight, neck circumference, body mass index, waist circumference, and drug dose (All P<0.001). We found that free triiodothyronine and free thyroxine were significantly negatively associated with abdominal fat area (P<0.01). There was no significant correlation between drug dose and abdominal fat area (P>0.05). Total cholesterol and low-density lipoprotein were significantly positively associated with abdominal fat area (P<0.01). However, high-density lipoprotein (P=0.06) was not correlated with abdominal fat area. Moreover, the results showed a significant negative correlation between thyroid hormones and lipids (P<0.001). Conclusion: After anti-thyroid medicine treatment, patients had elevated visceral fat area and subcutaneous fat area and altered lipid profiles. These changes may be one of the reasons why metabolic and cardiovascular diseases remain increased after thyroid function is restored.

Topical administration of GLP-1 eyedrops improves retinal ganglion cell function by facilitating presynaptic GABA release in early experimental diabetes.

ABSTRACT: Diabetic retinopathy is a prominent cause of blindness in adults, with early retinal ganglion cell (RGC) loss contributing to visual dysfunction or blindness. In the brain, defects in y-aminobutyric acid (GABA) synaptic transmission are associated with pathophysiological and neurodegenerative disorders, whereas glucagon-like peptide-1 (GLP-1) has demonstrated neuroprotective effects. However, it is not yet clear whether diabetes causes alterations in inhibitory input to RGCs and whether and how GLP-1 protects against neurodegeneration in the diabetic retina through regulating inhibitory synaptic transmission to RGCs. In the present study, we used the patch-clamp technique to record GABA subtype A receptor-mediated miniature inhibitory postsynaptic currents (mIPSCs) in RGCs from streptozotocin-induced diabetes model rats. We found that early diabetes (4 weeks of hyperglycemia) decreased the frequency of GABAergic mIPSCs in RGCs without altering their amplitude, suggesting a reduction in the spontaneous release of GABA to RGCs. Topical administration of GLP-1 eyedrops over a period of 2 weeks effectively countered the hyperglycemia-induced downregulation of GABAergic mIPSC frequency, subsequently enhancing the survival of RGCs. Concurrently, the protective effects of GLP-1 on RGCs in diabetic rats were eliminated by topical administration of exendin-9-39, a specific GLP-1 receptor antagonist, or SR95531, a specific antagonist of the GABA subtype A receptor. Furthermore, extracellular perfusion of GLP-1 was found to elevate the frequencies of GABAergic mIPSCs in both ON- and OFF-type RGCs. This elevation was shown to be mediated by activation of the phosphatidylinositol-phospholipase C/inositol 1,4,5-trisphosphate receptor/Ca2+/protein kinase C signaling pathway downstream of GLP-1 receptor activation. Moreover, multielectrode array recordings revealed that GLP-1 functionally augmented the photoresponses of ON-type RGCs. Optomotor response tests demonstrated that diabetic rats exhibited reductions in visual acuity and contrast sensitivity that were significantly ameliorated by topical administration of GLP-1. These results suggest that GLP-1 facilitates the release of GABA onto RGCs through the activation of GLP-1 receptor, leading to the de-excitation of RGC circuits and the inhibition of excitotoxic processes associated with diabetic retinopathy. Collectively, our findings indicate that the GABA system has potential as a therapeutic target for mitigating early-stage diabetic retinopathy. Furthermore, the topical administration of GLP-1 eyedrops represents a non-invasive and effective treatment approach for managing early-stage diabetic retinopathy.

Fabrication of a ß-CD-functionalized magnetic microporous organic network for effective enrichment and detection of fluoroquinolone antibiotics in water samples.

Fluoroquinolone (FQ) antibiotics, one of the leading environmental pollutants, have ecotoxic effects that can accumulate through ecosystems and harm human health. The determination of FQs is still difficult due to the complex matrix, many interfering factors, and low concentration. Hence, a magnetic microporous organic network (MON) composite denoted as Fe3O4@MON-NH2@CM-ß-CD with excellent FQ adsorption performance was prepared by ß-CD covalent modification of a MON. Based on the existence of π-π packing, hydrophobic interaction, and hydrogen bonding between Fe3O4@MON-NH2@CM-ß-CD and FQs, a new magnetic solid phase extraction (MSPE) method for the enrichment of FQs was developed. Under optimized MSPE conditions, five FQs were detected by HPLC-UV with good linearity (R2 ≥ 0.9989) in the range of 0.02-1 µg mL-1, and detection limits (S/N = 3) in the range of 0.0014-0.0023 µg mL-1. The satisfactory recoveries ranged from 93.1 to 116.2% with RSDs lower than 8.39% when applied to actual environmental water samples. These results revealed that Fe3O4@MON-NH2@CM-ß-CD as an adsorbent for MSPE had excellent performance for FQ extraction from real samples, and the MON material types were expanded through the functionalization of MONs, which would have great potential for further application in various analytical methods.

Constitutive model for shape memory polymer and its thermodynamic responses in finite element analysis.

BACKGROUND: As a new intelligent polymer material, shape memory polymer (SMP) was a potential orthodontic appliance material. OBJECTIVE: This study aimed to investigate the thermodynamic responses of SMP under different loads via finite element analysis (FEA). METHODS: FEA specimens with a specification of 0.1 × 0.1 × 1 mm were designed. One end of the specimen was fixed, and the other was subjected to displacement load. Different loading, cooling, and heating rates were separately exerted on the specimen in its shape recovery process and used to observe the responses of the SMP constitutive model. Furthermore, specimens with various tensile elongation and sectional areas were simulated and used to elucidate their effect on shape recovering force. RESULTS: The specimens obtained a similar stress of 0.5, 0.44, and 1.07 Mpa for different loading, cooling, and heating rates after a long time. The shape recovering force of specimen increased from 0.0102 to 0.0315 N when the elongation improved from 10% to 40% and to 0.0408 N when the sectional areas were expanded to 0.2 × 0.2 mm. CONCLUSION: The stiffness of SMP was small at a high temperature but large at a low temperature. The effects of the loading, cooling, and heating rates on SMP can be eliminated after a long time. Furthermore, it was possible to increase the recovering force by increasing the elongation or expanding the sectional area of the specimen. The force was quadratically dependent on the elongation ratio.

Experimental study of slow-released Angiogenin by silicon micro-needle in improving blood support to multiple-territory perforator flaps in rats.

This research aimed to investigate the effect of slow-released angiogenin by silicon micro-needle on angiogenesis in the Choke zone of dorsal multiple-territory perforator flap in rats, as well as its mechanism. Thirty-six adult Sprague-Dawley (SD) rats were randomly divided into control group, model group, and four experimental groups. In model group, slow-release saline through a silicon micro-needle was placed in choke II zone of the flap 7 days before the operation. For rats in four experimental groups, angiogenin was released via micro-needle in the choke I and choke II zones of the cross-zone flap 7 days before and 3 days before flap surgery, respectively. A 12 cm × 3 cm cross-zone perforator flap model was made on the back of all five groups. The flap survival rate in slow-release angiopoietin group was statistically higher than that in model group (P<0.05). Angiogenin in choke zone of the flap was increased in slow-release angiogenin group (P<0.05). In slow-release angiogenin group, the micro-vessel density was increased and the arteriovenous diameter was decreased, while the arteriovenous diameter was increased in model group (P<0.05). The levels of vascular endothelial growth factor A (VEGF-A) and angiotensin 1 (ANG-1) in choke zone were both elevated in slow-release angiogenin group (P<0.05). The expression of CD31 was significantly elevated in flaps of experimental groups (P<0.05). Micro-needle to slow release Angiogenin can increase the drug concentration in the tissues of the choke zone, promote the vascularization of rat dorsal crossover area perforator flap, reduce the possibility of flap ischemic necrosis, and improve the flap survival rate.

Roflumilast ameliorates GAN diet-induced non-alcoholic fatty liver disease by reducing hepatic steatosis and fibrosis in ob/ob mice.

Non-alcoholic fatty liver disease (NAFLD) is a highly prevalent progressive liver disease. Currently, there is only one drug for NAFLD treatment, and the options are limited. Phosphodiesterase-4 (PDE-4) inhibitors have potential in treating NAFLD. Therefore, this study aims to investigate the effect of roflumilast on NAFLD. Here, we fed ob/ob mice to induce the NAFLD model by GAN diet. Roflumilast (1 mg/kg) was administered orally once daily. Semaglutide (20 nmol/kg), used as a positive control, was injected subcutaneously once daily. Our findings showed that roflumilast has beneficial effects on NAFLD. Roflumilast prevented body weight gain and improved lipid metabolism in ob/ob-GAN NAFLD mice. In addition, roflumilast decreased hepatic steatosis by down-regulating the expression of hepatic fatty acid synthesis genes (SREBP1c, FASN, and CD36) and improving oxidative stress. Roflumilast not only reduced liver injury by decreasing serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, but also ameliorated hepatic inflammation by reducing the gene expression of proinflammatory cytokines (TNF-α, IL-1ß, and IL-6). Roflumilast lessened liver fibrosis by inhibiting the expression of fibrosis mRNA (TGFß1, α-SMA, COL1a1, and TIMP-1). Collectively, roflumilast could ameliorate NAFLD, especially in reducing hepatic steatosis and fibrosis. Our findings suggested a PDE-4 inhibitor roflumilast could be a potential drug for NAFLD.

Spliceosomal snRNAs, the Essential Players in pre-mRNA Processing in Eukaryotic Nucleus: From Biogenesis to Functions and Spatiotemporal Characteristics.

Spliceosomal small nuclear RNAs (snRNAs) are a fundamental class of non-coding small RNAs abundant in the nucleoplasm of eukaryotic cells, playing a crucial role in splicing precursor messenger RNAs (pre-mRNAs). They are transcribed by DNA-dependent RNA polymerase II (Pol II) or III (Pol III), and undergo subsequent processing and 3' end cleavage to become mature snRNAs. Numerous protein factors are involved in the transcription initiation, elongation, termination, splicing, cellular localization, and terminal modification processes of snRNAs. The transcription and processing of snRNAs are regulated spatiotemporally by various mechanisms, and the homeostatic balance of snRNAs within cells is of great significance for the growth and development of organisms. snRNAs assemble with specific accessory proteins to form small nuclear ribonucleoprotein particles (snRNPs) that are the basal components of spliceosomes responsible for pre-mRNA maturation. This article provides an overview of the biological functions, biosynthesis, terminal structure, and tissue-specific regulation of snRNAs.

Protective Effects of Polysaccharide of Atractylodes Macrocephala Koidz against Porcine Aortic Valve Endothelial Cells Damage Induced by di (2-ethylhexyl) Phthalate.

The activation, injury, and dysfunction of endothelial cells are considered to be the initial key events in the development of atherosclerosis. Di (2-ethylhexyl) phthalate (DEHP), a prevalent organic pollutant, can cause damage to multiple organs. Polysaccharide of Atractylodes macrocephala Koidz (PAMK) is a bioactive compound extracted from A. macrocephala Koidz with various biological activities. This study investigates the protective effects of PAMK on porcine aortic valve endothelial cells (PAVEC) damaged by DEHP. PAVECs treated with DEHP alone or with PAMK showed reduced cell apoptosis and death in PAMK-pretreated cells. PAMK up-regulated Bcl-2 expression and down-regulated Bax protein, suppressing apoptosis. Flow cytometry analysis demonstrated that PAMK protected PAVECs from DEHP-induced damage. These findings suggest that PAMK inhibits cell apoptosis and protects against DEHP damage in endothelial cells.

Synthesis and Characterization of a Temperature-Sensitive Microcapsule Gelling Agent for High-Temperature Acid Release.

Deep, high-temperature carbonate reservoirs, represented by the Chuanzhong-Gaomo Block and the Penglai Gas Field, have become important supports for increased storage and production in Sichuan Basin. However, acidization in high-temperature to ultrahigh-temperature reservoirs faces several technical challenges, such as fast acid-rock reaction rates, limited acid corrosion distances, and high risks of tubular corrosion. In this study, a novel high-temperature-resistant microencapsulated gelling agent GLE-3 was prepared using N-isopropylacrylamide (NIPAM) as the wall material, acrylamide (AM), 2-acrylamido-2-methylpropanesulfonic acid (AMPS), and N-vinylcaprolactam (NVCL) as the core materials, and N,N'-methylenebis(acrylamide) (MBA) as the cross-linking agent through inverse emulsion polymerization. GLE-3 was structurally characterized using infrared spectroscopy, transmission electron microscopy, and particle size analysis, and its properties were evaluated. The results showed that GLE-3 exhibited uniform particle size distribution ranging from 10 to 100 µm. Under high-temperature conditions of 180 °C and a shear rate of 170 s-1, the viscosity of the gel acid solution remained above 27.8 mPa·s, with a viscosity retention rate of 63.76%. Compared to GLE-1 (uncapsulated), GLE-3 demonstrated improved thermal stability and shear stability after microencapsulation. After 60 min of shearing at 180 °C and shear rate of 170 s-1, the viscosity retention rate was 88.99%. Furthermore, under 180 °C conditions, GLE-3 exhibited good high-temperature slow-release performance compared to GLE-1, which unencapsulated with the same raw materials. By increasing the viscosity of the gel acid, delaying the acid-rock reaction rate, and providing high-temperature slow-release effects, the high-temperature resistance of the acid system was enhanced, ultimately achieving deep acidization in high-temperature reservoirs.

Construction and alidation of a severity prediction model for acute pancreatitis based on CT severity index: A retrospective case-control study.

To construct and internally and externally validate a nomogram model for predicting the severity of acute pancreatitis (AP) based on the CT severity index (CTSI).A retrospective analysis of clinical data from 200 AP patients diagnosed at the Hefei Third Clinical College of Anhui Medical University from June 2019 to June 2022 was conducted. Patients were classified into non-severe acute pancreatitis (NSAP, n = 135) and severe acute pancreatitis (SAP, n = 65) based on final clinical diagnosis. Differences in CTSI, general clinical features, and laboratory indicators between the two groups were compared. The LASSO regression model was used to select variables that might affect the severity of AP, and these variables were analyzed using multivariate logistic regression. A nomogram model was constructed using R software, and its AUC value was calculated. The accuracy and practicality of the model were evaluated using calibration curves, Hosmer-Lemeshow test, and decision curve analysis (DCA), with internal validation performed using the bootstrap method. Finally, 60 AP patients treated in the same hospital from July 2022 to December 2023 were selected for external validation.LASSO regression identified CTSI, BUN, D-D, NLR, and Ascites as five predictive factors. Unconditional binary logistic regression analysis showed that CTSI (OR = 2.141, 95%CI:1.369-3.504), BUN (OR = 1.378, 95%CI:1.026-1.959), NLR (OR = 1.370, 95%CI:1.016-1.906), D-D (OR = 1.500, 95%CI:1.112-2.110), and Ascites (OR = 5.517, 95%CI:1.217-2.993) were independent factors influencing SAP. The established prediction model had a C-index of 0.962, indicating high accuracy. Calibration curves demonstrated good consistency between predicted survival rates and actual survival rates. The C-indexes for internal and external validation were 0.935 and 0.901, respectively, with calibration curves close to the ideal line.The model based on CTSI and clinical indicators can effectively predict the severity of AP, providing a scientific basis for clinical decision-making by physicians.

Association of Aldosterone, Renin, and Aldosterone to Renin Ratio with Metabolic Profile in Primary Aldosteronism.

Purpose: This study aimed to investigate the glycometabolism, fat mass, and lean mass in primary aldosteronism (PA) during disease progression. Patients and Methods: Patients diagnosed with PA and healthy controls (HCs) were enrolled. A flash glucose monitoring system (FGMS) and dual-energy X-ray absorptiometry (DEXA) were used to measure glucose variability and glucose target rate along with fat mass and lean mass. Comparative analysis of FGMS- or DEXA-derived parameters along with correlation analyses between these parameters and PA progression were performed. Results: Increased glucose variability and poor glucose target rate, along with an increased proportion of truncal fat mass, and decreased proportion of appendicular lean mass, were identified in PA group compared to those in HCs. Plasma aldosterone concentration was positively correlated with glucose variability and poor glucose target rate. Plasma renin concentration was positively correlated with the proportion of truncal fat mass and lean mass, and negatively correlated with the proportion of appendicular fat mass. Aldosterone-to-renin ratio was negatively correlated with the proportion of truncal fat mass and lean mass, and positively correlated with the proportion of appendicular fat mass. Conclusion: Patients with PA presented significant differences in glycometabolism, fat mass, and lean mass compared with HCs, and these alterations correlated with PA progression.

Gradient gyroid Ti6Al4V scaffolds with TiO2 surface modification: Promising approach for large bone defect repair.

Large bone defects, particularly those exceeding the critical size, present a clinical challenge due to the limited regenerative capacity of bone tissue. Traditional treatments like autografts and allografts are constrained by donor availability, immune rejection, and mechanical performance. This study aimed to develop an effective solution by designing gradient gyroid scaffolds with titania (TiO2) surface modification for the repair of large segmental bone defects. The scaffolds were engineered to balance mechanical strength with the necessary internal space to promote new bone formation and nutrient exchange. A gradient design of the scaffold was optimized through Finite Element Analysis (FEA) and Computational Fluid Dynamics (CFD) simulations to enhance fluid flow and cell adhesion. In vivo studies in rabbits demonstrated that the G@TiO2 scaffold, featuring a gradient structure and TiO2 surface modification, exhibited superior healing capabilities compared to the homogeneous structure and TiO2 surface modification (H@TiO2) and gradient structure (G) scaffolds. At 12 weeks post-operation, in a bone defect representing nearly 30 % of the total length of the radius, the implantation of the G@TiO2 scaffold achieved a 27 % bone volume to tissue volume (BV/TV) ratio, demonstrating excellent osseointegration. The TiO2 surface modification provided photothermal antibacterial effects, enhancing the scaffold's biocompatibility and potential for infection prevention. These findings suggest that the gradient gyroid scaffold with TiO2 surface modification is a promising candidate for treating large segmental bone defects, offering a combination of mechanical strength, bioactivity, and infection resistance.

Study on the Effect of Electrolytes on Processing Efficiency and Accuracy of Titanium Alloy Utilizing Laser and Shaped Tube Electrochemical Machining.

Electrochemical machining (ECM) has become more prevalent in titanium alloy processing. However, the presence of the passivation layer on the titanium alloys significantly impacts the performance of ECM. In an attempt to overcome the passivation effects, a high-temperature electrolyte or the addition of halogen ions to the electrolyte has been used. Still, it often results in compromised machining accuracy and surface roughness. This study applied laser and shaped tube electrolytic machining (Laser-STEM) for titanium alloy drilling, where the laser was guided to the machining zone via total internal reflection. The performance of Laser-STEM using different types of electrolytes was compared. Further, the effects of laser power and pulse voltage on the machining side gap, material removal rate (MRR), and surface roughness were experimentally studied while drilling small holes in titanium alloy. The results indicated that the use of passivating electrolytes improved the machining precision, while the MRR decreased with an increase in laser power during Laser-STEM. The MRR showed an increase while using aggressive electrolytes; however, at the same time, the machining precision deteriorated with the increase in laser power. Particularly, the maximum feeding rate of 6.0 mm/min for the tool electrode was achieved using NaCl solution as the electrolyte during Laser-STEM, marking a 100% increase compared to the rate without the use of a laser. Moreover, the model and equivalent circuits were also established to illustrate the material removal mechanisms of Laser-STEM in different electrolytes. Lastly, the processing of deep small holes with a diameter of 1.5 mm, a depth of 38 mm, and a surface roughness of Ra 2 µm was achieved via Laser-STEM without the presence of a recast layer and heat-affected zones. In addition, the cross-inner flow channels in the titanium alloys were effectively processed.

Resveratrol alleviates inorganic arsenic-induced ferroptosis in chicken brain via activation of the Nrf2 signaling pathway.

Inorganic arsenic (iAs) is a well-recognized environmental pollutant that induces severe brain injury in humans and animals. The antioxidant, anti-inflammatory, and anti-ferroptotic effects of resveratrol (Res) were demonstrated in multiple animal experiments. In order to investigate the protective effect of Res on iAs-induced chicken brain injury, the 40 chickens (19-d-old, female) brain injury model was established by oral administration of iAs (30 mg/L NaAsO2) for 6 weeks. All chickens had free access to both food and water during the experiment. The biochemical indices, hematoxylin-eosin staining, and related protein levels of oxidative stress, inflammation and ferroptosis were then determined. Our results indicated that Res (1000 mg/kg) alleviated the iAs-induced brain injury after 6 weeks of oral administration, primarily by reducing the interleukin-1ß mRNA expression and nuclear factor kappa B and malondialdehyde level, and increasing the antioxidant enzyme activity and the mRNA expression of nuclear factor erythroid 2-related factor 2 (Nrf2). Taken together, our study demonstrates that Res effectively inhibits iAs-induced oxidative stress and ferroptosis by mediating the Nrf2 signaling pathway, thereby alleviating iAs-induced brain injury in chickens. This is the first time that the amelioration effects of Res on the iAs-induced brain have been investigated from multiple perspectives.

Comparative biomechanics of all-on-4 and vertical implant placement in asymmetrical mandibular: a finite element study.

BACKGROUND: Clinical scenarios frequently present challenges when patients exhibit asymmetrical mandibular atrophy. The dilemma arises: should we adhere to the conventional All-on-4 technique, or should we contemplate placing vertically oriented implants on the side with sufficient bone mass? This study aims to employ three-dimensional finite element analysis to simulate and explore the biomechanical advantages of each approach. METHODS: A finite element model, derived from computed tomography (CT) data, was utilized to simulate the nonhomogeneous features of the mandible. Three configurations-All-on-4, All-on-5-v and All-on-5-o were studied. Vertical and oblique forces of 200 N were applied unilaterally, and vertical force of 100 N was applied anteriorly to simulate different masticatory mechanisms. The maximum von Mises stresses on the implant and framework were recorded, as well as the maximum equivalent strain in the peri-implant bone. RESULTS: The maximum stress values for all designs were located at the neck of the distal implant, and the maximum strains in the bone tissue were located around the distal implant. The All-on-5-o and All-on-5-v models exhibited reduced stresses and strains compared to All-on-4, highlighting the potential benefits of the additional implant. There were no considerable differences in stresses and strains between the All-on-5-o and All-on-5-v groups. CONCLUSIONS: With the presence of adequate bone volume on one side and severe atrophy of the contralateral bone, while the "All-on-4 concept" is a viable approach, vertical implant placement optimizes the transfer of forces between components and tissues.