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Earthquake-induced rock landslides in the eastern mountains of the Tibetan Plateau, especially landslides with weak interlayers pose a significant threat to major construction projects. Prestressed anchor cable is one of the main reinforcement methods of rock slopes. This paper combines shaking table model tests and numerical simulation to study the reinforcement effect and dynamic response characteristics of prestressed anchor cables applied to rock slopes with weak interlayers under strong earthquakes. The research results show that prestressed anchor cables can effectively reinforce slopes with weak interlayers. A small cable inclination, a small spacing and a high prestress are recommended in the seismic reinforcement design of prestressed anchor cable. In addition, the characteristics of slope progressive damage and prestress loss under the earthquake are found by the shaking table test. The results have been applied in hazard prevention and control of rock slopes on the Chengdu-Lanzhou Railway at the eastern Qinghai-Tibet Plateau.
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Limb-shaking transient ischemic attack (TIA) is a rare manifestation of carotid-occlusive damage. This case report highlights the importance of accurate diagnosis and treatment of bilateral ballism as limb-shaking TIA. Superficial cephalic artery and mid-large artery anastomosis was performed after the initial acute treatment, and involuntary limb shaking disappeared.
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Timber-framed masonry structures are widely used around the world, and their seismic performance is generally poor. Most of them have not been seismically strengthened. In areas with high seismic fortification intensity, there are great potential safety hazards. And it is urgent to carry out effective seismic reinforcement. However, due to the complicated construction process of the existing reinforcement technology, the poor durability of the reinforcement materials, and the significant disturbance to the life of the original residents, an efficient single-story timber-framed masonry structure reinforcement technology suitable for comprehensive promotion and application has not been explored. In this paper, a fiber-reinforced cement mortar (FRCM) material was proposed. A 1/2 scale model of a single-story timber-framed masonry structure was taken as the research object. The method of strengthening a single-story timber-framed masonry structure with FRCM layer was adopted. And the shaking table test of the model before and after reinforcement was carried out in turn. The dynamic characteristics, failure modes, acceleration response and displacement response of the FRCM layer-strengthened structure were analyzed through comparisons of the two cases. The experimental results showed that the FRCM layer significantly improved the seismic performance of the seismic-damaged single-story timber-framed masonry structures. The X- and Y-direction natural frequencies of the model structure were increased by 31.30% and 30.22%, respectively, after the structure was strengthened with FRCM. During a rare eight-degree earthquake, the inter-story displacement angles in the X- and Y-direction of the unreinforced model reached 1/98 and 1/577, respectively, and the structure was destroyed, while the inter-story displacement angle of the FRCM-reinforced model was only 1/2 of that the unreinforced model. During a rare nine-degree earthquake, the X-direction inter-story displacement angle of the model strengthened with FRCM reached 1/78 and the Y-direction inter-story displacement angle reached 1/178. At this time, the reinforced model structure was destroyed, but there was no collapse of the structural components, which met the seismic design objectives of "operational under the design minor seismic intensity, repairable damage under the design seismic precautionary intensity, and collapse prevention under the design rare seismic intensity", which proved that the FRCM layer was an effective and feasible way to strengthen the existing single-story wood-masonry rural building.
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Force-related discoloration materials are highly valuable because of their characteristics of visualization, easy operation, and environment friendliness. Most force-related discoloration materials focus on polymers and depend on bond scission, which leads to insensitivity and unrecoverable. Small-molecule systems based on well-defined molecular structures and simple composition with high sensitivity would exhibit considerable mechanochromic potential. However, to date, researches about force-related discoloration materials based on small molecule solution remain limited and are rarely reported. In this study, we developed a repeatable and instantaneous discoloration small molecule solution system by simple one-pot synthesis method. It exhibited an instantaneous chromic change from yellowish to dark green under shaking and reverting back to yellow within 1â minute after removal of the shaking. Experimental results confirmed that the discoloration mechanism is attributed to the oscillation accelerating the production of unstable ortho-OH phenoxyl radical. The newly developed shaking-induced discoloration small molecule system (SDSMS) promises in field of mechanical force sensing and optical encryption.
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Shaking constitutes a pivotal technique for enhancing black tea quality; nevertheless, its impact on the transformation mechanism of non-volatile metabolites (NVMs) in black tea remains obscure. The present study aimed to investigate the impact of shaking-withering methods (SWM) and traditional-withering methods (TWM) on black tea quality and NVMs conversion. A total of 57 NVMs and 14 objective quantitative indicators were obtained. SWM enhanced sweetness and umami taste, as well as appearance and liquor color brightness of black tea. Eight key differential NVMs were identified by multivariate statistical and dose over threshold value analysis. Metabolic pathway and evolution law analysis revealed that SWM enhanced the oxidation of catechins and flavonol glycosides, promoted the decarboxylation of glutamic acid, then facilitated the formation of theaflavin-3,3'-digallate, finally enhanced the taste and color quality of black tea. This study offers theoretical guidance and technical support for the targeted processing of high-quality black tea.
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Camellia sinensis , Metabolómica , Gusto , Té , Té/química , Camellia sinensis/química , Camellia sinensis/metabolismo , Aromatizantes/química , Aromatizantes/metabolismo , Humanos , Manipulación de Alimentos , Catequina/metabolismo , Catequina/química , Catequina/análisis , Control de CalidadRESUMEN
We describe a method for polyethyleneimine (PEI)-mediated transient transfection of suspension-adapted Chinese hamster ovary (CHO-DG44) cells for protein expression applicable at scales from 2 mL to 2 L. The method involves transfection at a high cell density (5 × 106 cells/mL) by direct addition of plasmid DNA (pDNA) and PEI to the culture and subsequent incubation at 31 °C with agitation by orbital shaking. This method requires 0.3 mg/L of coding pDNA, 2.7 mg/L of nonspecific (filler) DNA, and 15 mg/L of PEI. The production phase is performed at 31 °C in the presence of 0.25% N,N-dimethylacetamide (DMA). If desired, the method can be modified to avoid use of DMA by increasing the amount of coding DNA. We also provide information on culture vessel options, recommended working volumes, and recommended shaking speeds for transfections at scales from 2 mL to 2 L.
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Cricetulus , Plásmidos , Polietileneimina , Transfección , Animales , Células CHO , Polietileneimina/química , Transfección/métodos , Plásmidos/genética , Expresión Génica , Cricetinae , ADN/genéticaRESUMEN
CHO cell pools with desirable characteristics of high titer and consistent product quality are useful for rapid production of recombinant proteins. Here, we describe the generation of CHO cell pools using the piggyBac transposon system for mediating gene integration. The method describes the co-transfection of cells with the donor plasmid (coding for the gene of interest) and the helper plasmid (coding for the transposase) using polyethyleneimine (PEI). This is followed by a genetic selection for the generation of a cell pool. The resulting cell pool can be used to start a batch or fed-batch culture. Alternatively, it can be used for generation of clonal cell lines or generation of cell banks for future use.
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Cricetulus , Elementos Transponibles de ADN , Transfección , Animales , Células CHO , Elementos Transponibles de ADN/genética , Transfección/métodos , Plásmidos/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Polietileneimina/química , Transposasas/genética , Transposasas/metabolismo , Vectores Genéticos/genéticaRESUMEN
A TLD is a passive damping device that works by dissipating energy through the sloshing of the liquid and the effect of wave breaking, thereby controlling the vibrations of the structure. One of the applications where TLDs are of great interest is in the case of industrial chimneys since these structures often have a very low natural frequency, which can be easily achieved in a control device of this type. The main objective of this study is to evaluate the behaviour of an annular TLD composed of multiple cells through laboratory tests and investigate if it is adequate to design it as an agglomeration of smaller rectangular TLDs. The influence of the amplitude of displacement on the behaviour of the annular TLD will also be analysed. The tests were performed on a shaking table and recurring with pendulums of the same length but of different masses. Three reservoirs were studied as TLDs: a rectangular one, a cell of an annular TLD and a quarter-ring of an annular TLD. This study concluded that the analytical methods developed in previous studies were, in general, adequate for the design of a rectangular TLD and that it was reasonable to design the annular TLD studied as a combination of rectangular ones, as its cells were a close match to a rectangle of similar dimensions. It was also concluded that a compartmentalised annular TLD is an adequate solution for the vibration control of structures with high displacements.
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Black teas harvested during the summer season usually have the defect of low aroma intensity, resulting in unacceptability from consumers. The shaking and standing (SS) process is key to the production of oolong tea and is believed to significantly improve the aroma quality. However, the specific effects of the shaking process on the aroma quality of black tea have not been elucidated. SSBT has a higher aroma intensity than BT, especially floral and sweet odors. By Aroma Extract Dilution Analysis (AEDA), 27 volatiles with flavor dilution factor (FD) above 8 were selected, of which 20 had odor activity values (OAV) values above 1; among them, 9 floral and sweet volatiles with high OAV were linalool (485 for BT, 918 for SSBT), (E)-ß-ionone (389, 699), geraniol (315, 493), ß-myrcene (25, 62), (E)-2-hexenal (2, 7), phenylacetaldehyde (44, 75), (Z)-3-hexenyl hexanoate (19, 41), 1-hexanol (9, 26), and 2-phenylethanol (2,3). Aroma reconstitution of these 20 volatiles showed reliable results of floral, sweet, fruity, and roasted odors, further validating the aroma and intensity profiles of the key odorants. Overall, our results reveal that the metabolite mechanism of the SS process improves the aroma quality of black tea, providing a theoretical basis and guiding measures for the production of high-aroma black tea.
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Camellia sinensis , Odorantes , Té , Compuestos Orgánicos Volátiles , Odorantes/análisis , Compuestos Orgánicos Volátiles/química , Compuestos Orgánicos Volátiles/análisis , Camellia sinensis/química , Té/química , Manipulación de Alimentos , Humanos , Aromatizantes/química , Estaciones del Año , Gusto , Cromatografía de Gases y Espectrometría de MasasRESUMEN
BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is a natural focal disease transmitted mainly by tick bites, and the causative agent is SFTS virus (SFTSV). SFTS can rapidly progress to severe disease, with multiple-organ failure (MOF) manifestations such as shock, respiratory failure, disseminated intravascular coagulation (DIC) and death, but cases of SFTS patients with central nervous system (CNS) symptoms onset and marked persistent involuntary shaking of the perioral area and limbs have rarely been reported. CASE PRESENTATION: A 69-year-old woman with fever and persistent involuntary shaking of the perioral area and limbs was diagnosed with SFTS with CNS symptom onset after metagenomic next-generation sequencing (mNGS) of cerebrospinal fluid (CSF) and peripheral blood identified SFTSV. The patient developed a cytokine storm and MOF during the course of the disease, and after aggressive antiviral, glucocorticoid, and gamma globulin treatments, her clinical symptoms improved, her laboratory indices returned to normal, and she had a good prognosis. CONCLUSION: This case gives us great insight that when patients with CNS symptoms similar to those of viral encephalitis combined with thrombocytopenia and leukopenia are encountered in the clinic, it is necessary to consider the possibility of SFTS involving the CNS. Testing for SFTSV nucleic acid in CSF and blood (mNGS or polymerase chain reaction (PCR)) should be carried out, especially in critically ill patients, and treatment should be given accordingly.
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Phlebovirus , Síndrome de Trombocitopenia Febril Grave , Humanos , Femenino , Anciano , Síndrome de Trombocitopenia Febril Grave/diagnóstico , Phlebovirus/genética , Phlebovirus/aislamiento & purificación , Insuficiencia Multiorgánica/virología , Insuficiencia Multiorgánica/diagnóstico , Insuficiencia Multiorgánica/etiologíaRESUMEN
BACKGROUND: To determine whether sensory nerve conduction stimulus threshold measurements of the infraorbital nerve are able to differentiate horses with idiopathic trigeminal-mediated headshaking (i-TMHS) from healthy horses and from horses with secondary trigeminal-mediated headshaking (s-TMHS). In a prospective trial, headshaking horses were examined using a standardized diagnostic protocol, including advanced diagnostics such as computed tomography and 3-Tesla-magnetic resonance imaging (MRI), to differentiate s-TMHS from i-TMHS. Clinically healthy horses served as controls. Within this process, patients underwent general anesthesia, and the minimal sensory nerve conduction stimulus threshold (SNCT) of the infraorbital nerve was measured using a bipolar concentric needle electrode. Sensory nerve action potentials (SNAP) were assessed in 2.5-5 mA intervals. Minimal SNCT as well as additional measurements were calculated. RESULTS: In 60 horses, SNAP could be recorded, of which 43 horses had i-TMHS, six had suspected s-TMHS, three horses had non-facial headshaking, and eight healthy horses served as controls. Controls had a minimal SNCT ≥ 15 mA, whereas 14/43 horses with i-TMHS and 2/6 horses with s-TMHS showed a minimal SNCT ≤ 10 mA. Minimal SNCT ≤ 10 mA showed 100% specificity to distinguish TMHS from controls, but the sensitivity was only 41%. CONCLUSION: A minimal SNCT of the infraorbital nerve ≤ 10 mA was able to differentiate healthy horses from horses with TMHS. Nevertheless, a higher minimal SNCT did not exclude i-TMHS or s-TMHS and minimal SNCT does not distinguish s-TMHS from i-TMHS.
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Enfermedades de los Caballos , Conducción Nerviosa , Animales , Caballos , Enfermedades de los Caballos/diagnóstico , Femenino , Masculino , Conducción Nerviosa/fisiología , Cabeza , Estudios Prospectivos , Nervio Trigémino/fisiologíaRESUMEN
Shake-flask culture, an aerobic submerged culture, has been used in various applications involving cell cultivation. However, it is not designed for forced aeration. Hence, this study aimed to develop a small-scale submerged shaking culture system enabling forced aeration into the medium. A forced aeration control system for multiple vessels allows shaking, suppresses volatilization, and is attachable externally to existing shaking tables. Using a specially developed plug, medium volatilization was reduced to less than 10%, even after 45 h of continuous aeration (~ 60 mL/min of dry air) in a 50 mL working volume. Escherichia coli IFO3301 cultivation with aeration was completed within a shorter period than that without aeration, with a 35% reduction in the time-to-reach maximum bacterial concentration (26.5 g-dry cell/L) and a 1.25-fold increase in maximum concentration. The maximum bacterial concentration achieved with aeration was identical to that obtained using the Erlenmeyer flask, with a 65% reduction in the time required to reach it.
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Medios de Cultivo , Escherichia coli , Escherichia coli/crecimiento & desarrollo , Volatilización , Medios de Cultivo/química , Reactores Biológicos/microbiología , Técnicas Bacteriológicas/métodosRESUMEN
The Chinese hamster ovarian (CHO) cells serve as a common choice in biopharmaceutical production, traditionally cultivated in stirred tank bioreactors (STRs). Nevertheless, the pursuit of improved protein quality and production output for commercial purposes demand exploration into new bioreactor types. In this context, inverted frustoconical shaking bioreactors (IFSB) present unique physical properties distinct from STRs. This study aims to compare the production processes of an antibody-based biotherapeutic in both bioreactor types, to enhance production flexibility. The findings indicate that, when compared to STRs, IFSB demonstrates the capability to produce an antibody-based biotherapeutic with either comparable or enhanced bioprocess performance and product quality. IFSB reduces shear damage to cells, enhances viable cell density (VCD), and improves cell state at a 5-L scale. Consequently, this leads to increased protein expression (3.70 g/L vs 2.56 g/L) and improved protein quality, as evidenced by a reduction in acidic variants from 27.0% to 21.5%. Scaling up the culture utilizing the Froude constant and superficial gas velocity ensures stable operation, effective mixing, and gas transfer. The IFSB maintains a high VCD and cell viability at both 50-L and 500-L scales. Product expression levels range from 3.0 to 3.6 g/L, accompanied by an improved acidic variants attribute of 20.6%-22.7%. The IFSB exhibits superior productivity and product quality, underscoring its potential for incorporation into the manufacturing process for antibody-based biotherapeutics. These results establish the foundation for IFSB to become a viable option in producing antibody-based biotherapeutics for clinical and manufacturing applications.
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As a passive motion and non-invasive treatment, theta-shaking exercise is considered an alternative to traditional active exercise for slowing down brain ageing. Here, we studied the influence of theta-shaking exercise on fibronectin type III domain containing 5/irisin (FNDC5/irisin) in the anterior nucleus of the thalamus, hippocampus, and medial prefrontal cortex (ATN-HPC-MPFC). Further, we assessed memory in senescence-accelerated prone mice (SAMP-10 mice) using a behavioural test to confirm the protective effect of theta-shaking exercise against age-related memory decline. SAMP-10 mice were subjected to theta-shaking exercise for 9-30 weeks. Mice then performed the T-maze test and passive avoidance task. Immunohistochemical analysis and ELISA were used to assess FNDC5/irisin, nerve growth factor (NGF), and neurotrophin 4/5 (NT4/5) expression in the ATN-HPC-MPFC. In the shaking group, FNDC5 was locally upregulated within the hippocampus and MPFC area rather than exhibiting even distribution throughout brain tissue. Irisin levels were generally higher in the control group. Meanwhile, hippocampal NGF levels were significantly higher in the shaking group, with no differences noted in neurotrophin levels. Theta-shaking preserved normal neurons in certain sub-regions. However, no beneficial changes in neuronal density were noted in the ATN. Theta-shaking exercise positively affects memory function in SAMP-10 mice. FNDC5 upregulation and higher levels of NGF, along with the potential involvement of irisin, may have contributed to the preservation of normal neuronal density in the hippocampus and MPFC subregions.
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AIMS: The adverse effects of sedentary behavior on obesity and chronic diseases are well established. However, the prevalence of sedentary behavior has increased, with only a minority of individuals meeting the recommended physical activity guidelines. This study aimed to investigate whether habitual leg shaking, a behavior traditionally considered unfavorable, could serve as an effective strategy to improve energy metabolism. MATERIALS AND METHODS: A randomized crossover study was conducted, involving 15 participants (mean [SD] age, 25.4 [3.6]; mean [SD] body mass index, 22 [3]; 7 women [46.7%]). The study design involved a randomized sequence of sitting and leg shaking conditions, with each condition lasting for 20 min. Energy expenditure, respiratory rate, oxygen saturation, and other relevant variables were measured during each condition. RESULTS: Compared to sitting, leg shaking significantly increased total energy expenditure [1.088 kj/min, 95% confidence interval, 0.69-1.487 kj/min], primarily through elevated carbohydrate oxidation. The average metabolic equivalent during leg shaking exhibited a significant increase from 1.5 to 1.8. Leg shaking also raised respiratory rate, minute ventilation, and blood oxygen saturation levels, while having no obvious impact on heart rate or blood pressure. Electromyography data confirmed predominant activation of lower leg muscles and without increased muscle fatigue. Intriguingly, a significant correlation was observed between the increased energy expenditure and both the frequency of leg shaking and the muscle mass of the legs. CONCLUSIONS: Our study provides evidence that habitual leg shaking can boost overall energy expenditure by approximately 16.3%. This simple and feasible approach offers a convenient way to enhance physical activity levels.
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Estudios Cruzados , Metabolismo Energético , Pierna , Humanos , Femenino , Adulto , Masculino , Adulto Joven , Conducta Sedentaria , Frecuencia Respiratoria , Frecuencia Cardíaca/fisiologíaRESUMEN
AIM: Crying seems to be a common trigger for abusive head trauma (AHT), which is the leading cause of fatalities from physical abuse in infants. Our objective was to evaluate knowledge of AHT, crying infants and correct behavioural measures in a general population. METHODS: An online questionnaire (LimeSurvey) was created to assess the risk of shaking. The online survey contained a total of 41 questions, including a demonstration of a previously recorded video in which an infant doll is shaken. RESULTS: A total of 319 people, 245 of them (76.8%) with own children, participated in the study. Almost all respondents (98.4%) were aware of serious injuries due to shaking, even to the point of death (98.1%). Most participants (97.5%) had heard the term 'shaking trauma' prior but did not receive any professional information, neither before nor after birth (85.2% or 86%), or during follow-up examinations (88.5%). The majority of the participants (95%) considered that useful coping strategies in infant crying were inappropriate. CONCLUSION: The consequences of shaking an infant were common knowledge in a normal population, whereas there was a knowledge gap regarding the management of excessive crying infants. Prevention programmes should mainly focus on male caregivers during postnatal care.
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Maltrato a los Niños , Traumatismos Craneocerebrales , Llanto , Síndrome del Bebé Sacudido , Humanos , Llanto/psicología , Masculino , Lactante , Recién Nacido , Femenino , Síndrome del Bebé Sacudido/prevención & control , Síndrome del Bebé Sacudido/diagnóstico , Adulto , Traumatismos Craneocerebrales/prevención & control , Conocimientos, Actitudes y Práctica en Salud , Encuestas y Cuestionarios , Adulto Joven , Persona de Mediana Edad , AdolescenteRESUMEN
BACKGROUND: Limb-shaking transient ischemic attack (LSTIA) is a rare neurological condition which presents with involuntary jerky movements of the arm or leg, often because of carotid stenosis or occlusion. Due to the rarity of the condition, the epidemiology of LSTIA is poorly understood and the disease is frequently misdiagnosed. There is no standard treatment to date. The purpose of this study was to provide an overview of the epidemiology of LSTIA and its current treatment options. METHODS: Embase, MEDLINE, Web of Science, Cochrane Central Register of Controlled Trials for randomized controlled trials, and Google Scholar were searched from database inception to December 30, 2023 for articles containing information on the epidemiology and treatment of LSTIA. An individual patient data meta-analysis (IPD-MA) was performed using data extracted from the included articles. Inclusion criteria were description of both the epidemiology and treatment of LSTIA in patients over the age of 18 with carotid stenosis/occlusion, confirmed by radiographic imaging. Exclusion criteria were studies focusing on pediatrics, no epidemiological data, internal carotid artery (ICA) stenosis/occlusion not radiologically confirmed, full text unavailable, full text not in English or Dutch, and non-original articles. RESULTS: Of the 8,855 articles screened, 55 articles containing 251 patients were included. Fifty articles harboring 81 patients were included in the IPD-MA, and 7 articles harboring 187 patients were included in the cohort analysis. The results of the IPD-MA showed that LSTIA was caused by unilateral ICA stenosis/occlusion in 29 patients (36%) and most often from bilateral ICA stenosis/occlusion in 52 patients (64%). Limb-shaking was unilateral in 66 patients (83%) and was accompanied by weakness in 27 patients (33%). The intervention with the highest success rate was endovascular intervention (carotid stenting or balloon angioplasty), as all 10 patients remained asymptomatic after treatment. The cohort analysis showed that LSTIA can be caused by both unilateral and bilateral carotid stenosis or occlusion. The prevalence within cohorts of TIA patients of LSTIA varied considerably from 3.5 to 29%. CONCLUSION: A large international clinical registry is warranted to gain a better understanding of the epidemiology of LSTIA. There is insufficient evidence available to suggest a standard treatment.
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Shaking stress studies are typically performed during formulation development to test the liability of a drug product towards interfacial stress occurring during transport, especially if a liquid formulation is desired. We evaluated various shaking procedures using a polyA-surrogate solution and verified our findings by eGFP-LNP cell-expression experiments. Shaking on an orbital shaker in vertical and horizontal orientations at increasing speeds from 300 to 600 rpm resulted in decreasing levels of encapsulated nucleic acid content, larger LNP sizes, and decreasing PDI. We report that vertical and horizontal shaking of both polyA- and eGFP-LNPs led to white deposits on the inner glass vial surface, depending on time, rpm, and temperature. Increasing the fill volume/smaller headspace (0.3 versus 0.9 mL fill) did not mitigate this phenomenon in the studied configuration, and the use of hydrophobic primary packaging even accelerated the formation of white deposits. In contrast, we demonstrated that a lyophilized polyA-LNP dosage form was less susceptible to shaking and maintained cake integrity and product properties. Multiple vortexing steps resulted in an increase in LNP size, PDI, and a decrease in encapsulated polyA content. We conclude that shaking experiments of nucleic acid-loaded LNPs in their final configuration at intended transport conditions need to be considered during technical development.
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Liposomas , Nanopartículas , ARN Mensajero , Estrés Mecánico , Temperatura , Nanopartículas/química , ARN Interferente PequeñoRESUMEN
This paper describes investigations in respect of the seismic performance of a large-span high-rise building in a mountainous area. The building consists of a 135 m high shear wall structure and a 174.5 m long steel truss structure, with dampers used to enhance the seismic performance. A 1/40 scale model of the prototype structure was designed, and shaking table tests was conducted. The experiments simulated the wave passage effect and slope amplification effect based on the building site and structural characteristics of the prototype structure. The seismic performance of the prototype structure was analyzed through the damage phenomenon, dynamic characteristics, and dynamic response of the model under earthquake effects. The results show that three seismic waves were delayed by about 0.4 s and amplified by about 1.6 times after passing through the steel frame with viscous dampers, which could effectively simulate the wave passage effect and slope amplification effect in the test. The maximum story drift ratios of the model shear wall structure and steel truss structure were 1/1258 and 1/455 for the SLE and 1/568 and 1/185 for the MCE. The damping devices played a key role in energy dissipation. As a result, this research provides a reference for the seismic design and shaking table testing of large-span high-rise buildings.
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When testing earthquake simulation shaking tables, it is commonly assumed that the test load, table, and actuator are integrated, which differs significantly from the actual situation and negatively impacts the accuracy of system waveform reproduction. This paper simplifies the connection between the three as a spring-damping model for simulation modeling. The effects of different load mass, different connection intrinsic frequency, different connection damping ratios, and other factors on the control performance of the system are analyzed, and based on the results of the analysis, a method to improve the effects of the connection characteristics on the performance of the system, called flexible connection reaction force compensation algorithm, is proposed. Resonance peaks caused by flexible connections reduce the effective bandwidth. To broaden the bandwidth and enhance system stability, the paper introduces a flexible connection force compensation algorithm based on a multi-parameter control algorithm to compensate for the interaction force caused by the connection characteristics. This compensation strategy expands the effective bandwidth, eliminates resonance peaks, improves the waveform correlation coefficient (CC), and reduces the root-mean-square error (RMSE).