Quantitative analysis of the protective performance of bicycle helmet with multi-direction impact protection system in oblique impact tests.

PURPOSE: The current study aimed to assess the protective performance of helmets equipped with multi-directional impact protection system (MIPS) under various oblique impact loads. METHODS: Initially, a finite element model of a bicycle helmet with MIPS was developed based on the scanned geometric parameters of an actual bicycle helmet. Subsequently, the validity of model was confirmed using the KASK WG11 oblique impact test method. Three different impact angles (30°, 45°, and 60°) and 2 varying impact speeds (5 m/s and 8 m/s) were employed in oblique tests to evaluate protective performance of MIPS in helmets, focusing on injury assessment parameters such as peak linear acceleration (PLA) and peak angular acceleration (PAA) of the head. RESULTS: The results demonstrated that in all impact simulations, both assessment parameters were lower during impact for helmets equipped with MIPS compared to those without. The PAA was consistently lower in the MIPS helmet group, whereas the difference in PLA was not significant in the no-MIPS helmet group. For instance, at an impact velocity of 8 m/s and a 30° inclined anvil, the MIPS helmet group exhibited a PAA of 3225 rad/s2 and a PLA of 281 g. In contrast, the no-MIPS helmet group displayed a PAA of 8243 rad/s2 and a PLA of 292 g. Generally, both PAA and PLA parameters decreased with the increase of anvil angles. At a 60° anvil angles, PAA and PLA values were 664 rad/s2 and 20.7 g, respectively, reaching their minimum. CONCLUSION: The findings indicated that helmets incorporating MIPS offer enhanced protection against various oblique impact loads. When assessing helmets for oblique impacts, the utilization of larger angle anvils and rear impacts might not adequately evaluate protective performance during an impact event. These findings will guide advancements in helmet design and the refinement of oblique impact test protocols.

Recent advances in the study of anesthesia-and analgesia-related mechanisms of S-ketamine.

Ketamine is a racemic mixture of equal amounts of R-ketamine and S-ketamine and is well known to anesthesiologists for its unique dissociative anesthetic properties. The pharmacological properties of ketamine, namely, its sympathetic excitation, mild respiratory depression, and potent analgesia, are still highly valued in its use as an anesthetic for some patients. In particular, since its advent, S-ketamine has been widely used as an anesthetic in many countries due to its increased affinity for NMDA receptors and its enhanced anesthetic and analgesic effects. However, the anesthetic and analgesic mechanisms of S-ketamine are not fully understood. In addition to antagonizing NMDA receptors, a variety of other receptors or channels may be involved, but there are no relevant mechanistic summaries in the literature. Therefore, the purpose of this paper is to review the mechanisms of action of S-ketamine on relevant receptors and systems in the body that result in its pharmacological properties, such as anesthesia and analgesia, with the aim of providing a reference for its clinical applications and research.

Transcutaneous electrical acupoint stimulation for reducing cognitive dysfunction in lumbar spine surgery: A randomized, controlled trail.

Objective: This study aimed to evaluate the effect of perioperative transcutaneous electrical acupoint stimulation (TEAS) on postoperative cognitive dysfunction (POCD) in older patients with lumbar spine surgery. Methods: Older patients (aged 60-80 years old) receiving lumbar spine surgery under general anesthesia were randomly divided into group A, 3-day intervention group; group B, 7-day intervention group; control group C, sham TEAS group, selected "Baihui" (GV 20) and "Dazhui" (GV 14) point was intervened once 30 min before operation with "HANS" transcutaneous electrical stimulation device, and then once a day after operation for 30 min each time. The primary outcome was the incidence of postoperative cognitive impairment assessed by the use of the Mini Mental Rating Scale (MMSE), patients developed POCD according to the Z score method. The secondary outcome was serum interleukin-6 (IL-6), tumor Necrosis factor α (TNF-α), neuron-specific enolase (NSE), and S100ß protein levels. Results: Three days after surgery, the incidence of POCD in groups A((22.4%)) and B ((18.3%)) were lower than those in group C ((42.9%)) (P < 0.05). There was no significant difference between groups A and B (P > 0.05). Seven days after surgery, the incidence of POCD in group B (18.3%) was lower than that in groups A (26.5%) and B (42.9%), and the comparison between groups B and C was statistically significant (P < 0.05). On the 3rd and 7th days after surgery, the levels of IL-6, TNF-α, NSE, and S100ß in the two TEAS groups were lower than those in the sham TEAS group (P < 0.01), but higher than the preoperative levels in the three groups (P < 0.01). Conclusion: It seems that Perioperative TEAS intervention could reduce the level of inflammatory factors IL-6, TNF-α in the blood of older patients with lumbar spine surgery, and reduce the incidence of POCD. Clinical trial registration: www.chictr.org.cn, identifier ChiCTR2200063030.

[Sorption Mechanism and Site Energy Distribution of Acetaminophen on Straw-derived Biochar].

As one of the large dosages of pharmaceutical and personal care products (PPCPs), acetaminophen is widely present in the water environment and presents potential environmental risks. Therefore, it is necessary to study the removal mechanism of acetaminophen from the environment. Based on the high-value conversion demand of agricultural straw resources in China, straw-derived biochar prepared by pyrolysis has a good application prospect for the sorption and purification of acetaminophen in water. However, the sorption process and mechanism of straw-derived biochar for acetaminophen remain unclear. Four types of straw (rice, wheat, maize, and bean straw) were chosen as raw materials, and straw-derived biochars were prepared through the pyrolysis method at 400℃ and 500℃. The batch sorption experiments were used to study the sorption of acetaminophen to different sources and different pyrolysis temperature biochars. The effect of humic acid and pH on the sorption process was also studied. The results showed that:based on the Freundlich and site energy distribution models, the sorption of acetaminophen on biochar at 500℃ biochar was significantly higher than that at 400℃ biochar (the sorption coefficient KF was 1.16-2.53 times higher), and 500℃ biochar had more high-energy sorption sites. For high-temperature pyrolysis biochar, the primary sorption mechanism was pore sorption and π-π effect; for low-temperature pyrolysis biochar, the primary sorption mechanism for removing acetaminophen was H-bonding. The presence of humic acid enhanced the sorption of acetaminophen, which was attributed to the strong interaction between the humic acid selected in the experiment and acetaminophen, thus promoting adsorption. The decrease in sorption capacity of biochar caused by the increasing pH was mainly attributed to the pore blockage resulting from the aggregation of acetaminophen molecules. The pore sorption and π-π interaction of acetaminophen on straw-derived biochar could be promoted by increasing pyrolysis temperature. These experiments on humic acid and pH show that straw-derived biochar is not affected by humic acid and has good sorption performance in a low pH environment.

Clinical Features of Central Retinal Vein Occlusion in Young Patients.

Retinal vein occlusion (RVO) is the second most common retinal vascular disease. Central RVO (CRVO), in which obstruction occurs posterior to the lamina cribrosa due to various causes, manifests with extensive venous tortuosity, dilatation of blood vessels in the four quadrants, and retinal hemorrhage. The presence of macular edema decreases visual acuity in patients with CRVO, especially in elderly patients with hypertension, hyperlipidemia, and diabetes. In the last decade, treatment modalities for CRVO have improved, with anti-vascular endothelial growth factor agents being widely used as treatment. However, there are cases of refractory or recurrent macular edema. Moreover, CRVO also occurs in young patients. This article reviews previous studies and case reports and summarizes the differences in etiological factors, clinical manifestations, treatment, and prognosis between young and elderly patients. Due to the low incidence of CRVO in young patients, clinical data from these age groups are limited. Hence, further studies are warranted to explore the differences between age groups to improve individualization of treatment of young patients.

Detection of Amyloid-ß(1-42) Aggregation With a Nanostructured Electrochemical Sandwich Immunoassay Biosensor.

Amyloid-ß(1-42) [Aß(1-42)] oligomer accumulations are associated with physiologic alterations in the brains of individuals with Alzheimer's disease. In this study, we demonstrate that a nanostructured gold electrode with deposited gold nanoparticles, induced via electrochemical impedance spectroscopy (EIS), may be used as an Aß(1-42) conformation biosensor for the detection of Alzheimer's disease. Monoclonal antibodies (12F4) were immobilized on self-assembled monolayers of the electrochemical sandwich immunoassay biosensor to capture Aß(1-42) monomers and oligomers. Western blot and fluorescence microscopy analyses were performed to confirm the presence of Aß(1-42) monomers and oligomers. EIS analysis with an equivalent circuit model was used to determine the concentrations of different Aß(1-42) conformations in this study. We identified conformations of Aß(1-42) monomers and Aß(1-42) oligomers using probe antibodies (12F4) by employing EIS. R Aß ( 1 - 42 ) indicates the sum resistance of impedance measured during Aß(1-42) immobilization. Δ R 12 F 4 refers to the concentration of probe antibody (12F4) binding with Aß(1-42). The concentration of Aß(1-42) oligomer was defined as the percentage of Aß(1-42) aggregation R 12 F 4 / R Aß ( 1 - 42 ) . The experimental results show that the biosensor has high selectivity to differentiate Aß(1-40) and Aß(1-42) monomers and Aß(1-42) oligomers and that it can detect Aß(1-42) oligomer accurately. The linear detection range for Aß(1-42) oligomers was between 10 pg/ml and 100 ng/ml. The limit of detection was estimated to be 113 fg/ml.

Peptide-based electrochemical sensor with nanogold enhancement for detecting rheumatoid arthritis.

Rheumatoid arthritis (RA), an autoimmune and chronic inflammatory disorder, is an incurable disease. We developed a peptide-based electrochemical sensor using electrochemical impedance spectroscopy that can be used to detect autoantibodies for RA diagnostics. We first validated that the developed peptide showed high sensitivity and could compliment the current gold standard method of an anti-cyclic citrullinated peptide antibody (anti-CCP) ELISA. The developed peptide can be modified on the nanogold surface of the working electrode of sensing chips through the method of a self-assembling monolayer. The sensing process was first optimized using a positive control cohort and a healthy control cohort. Subsequently, 10 clinically confirmed samples from RA patients and five healthy control samples were used to find the threshold value of the impedance between RA and healthy subjects. Furthermore, 10 clinically confirmed samples but with low values of anti-CCP autoantibodies were used to evaluate the sensitivity of the present method compared to the conventional method. The proposed method showed better sensitivity than the current conventional anti-CCP ELISA method.

Characteristics of Atmospheric Fine Particulate Matter (PM 2.5) Induced Differentially Expressed Proteins Determined by Proteomics and Bioinformatics Analyses.

OBJECTIVE: To screen the differentially expressed proteins (DEPs) in human bronchial epithelial cells (HBE) treated with atmospheric fine particulate matter (PM 2.5). METHODS: HBE cells were treated with PM 2.5 samples from Shenzhen and Taiyuan for 24 h. To detect overall protein expression, the Q Exactive mass spectrometer was used. Gene ontology (GO), Kyoto encyclopedia of genes and genomes (KEGG), and Perseus software were used to screen DEPs. RESULTS: Overall, 67 DEPs were screened in the Shenzhen sample-treated group, of which 46 were upregulated and 21 were downregulated. In total, 252 DEPs were screened in the Taiyuan sample-treated group, of which 134 were upregulated and 118 were downregulated. KEGG analysis demonstrated that DEPs were mainly enriched in ubiquitin-mediated proteolysis and HIF-1 signal pathways in Shenzhen PM 2.5 samples-treated group. The GO analysis demonstrated that Shenzhen sample-induced DEPs were mainly involved in the biological process for absorption of various metal ions and cell components. The Taiyuan PM 2.5-induced DEPs were mainly involved in biological processes of protein aggregation regulation and molecular function of oxidase activity. Additionally, three important DEPs, including ANXA2, DIABLO, and AIMP1, were screened. CONCLUSION: Our findings provide a valuable basis for further evaluation of PM 2.5-associated carcinogenesis.

Carnosine suppresses oxygen-glucose deprivation/recovery-induced proliferation and migration of reactive astrocytes of rats in vitro.

Glial scar formation resulted from excessive astrogliosis limits axonal regeneration and impairs recovery of function, thus an intervention to ameliorate excessive astrogliosis is crucial for the recovery of neurological function after cerebral ischemia. In this study we investigated the effects of carnosine, an endogenous water-soluble dipeptide (ß-alanyl-L-histidine), on astrogliosis of cells exposed to oxygen-glucose deprivation/recovery (OGD/R) in vitro. Primary cultured rat astrocytes exhibited a significant increase in proliferation at 24 h recovery after OGD for 2 h. Pretreatment with carnosine (5 mmol/L) caused G1 arrest of reactive astrocytes, significantly attenuated OGD/R-induced increase in cyclin D1 protein expression and suppressed OGD/R-induced proliferation of reactive astrocytes. Carnosine treatment also reversed glycolysis and ATP production, which was elevated at 24 h recovery after OGD. A marked increase in migration of reactive astrocytes was observed at 24 h after OGD, whereas carnosine treatment reversed the expression levels of MMP-9 and suppressed the migration of astrocytes. Furthermore, carnosine also improved neurite growth of cortical neurons co-cultured with astrocytes under ischemic conditions. These results demonstrate that carnosine may be a promising candidate for inhibiting astrogliosis and promoting neurological function recovery after ischemic stroke.

Development of a piezoelectric vacuum sensing component for a wide pressure range.

In this study, we develop a clamped-clamped beam-type piezoelectric vacuum pressure sensing element. The clamped-clamped piezoelectric beam is composed of a PZT layer and a copper substrate. A pair of electrodes is set near each end. An input voltage is applied to a pair of electrodes to vibrate the piezoelectric beam, and the output voltage is measured at the other pair. Because the viscous forces on the piezoelectric beam vary at different air pressures, the vibration of the beam depends on the vacuum pressure. The developed pressure sensor can sense a wide range of pressure, from 6.5 × 10(-6) to 760 Torr. The experimental results showed that the output voltage is inversely proportional to the gas damping ratio, and thus, the vacuum pressure was estimated from the output voltage.