Realization of digital twin for dynamic control toward sample variation of ion exchange chromatography in antibody separation.

Digital twin (DT) is a virtual and digital representation of physical objects or processes. In this paper, this concept is applied to dynamic control of the collection window in the ion exchange chromatography (IEC) toward sample variations. A possible structure of a feedforward model-based control DT system was proposed. Initially, a precise IEC mechanistic model was established through experiments, model fitting, and validation. The average root mean square error (RMSE) of fitting and validation was 8.1% and 7.4%, respectively. Then a model-based gradient optimization was performed, resulting in a 70.0% yield with a remarkable 11.2% increase. Subsequently, the DT was established by systematically integrating the model, chromatography system, online high-performance liquid chromatography, and a server computer. The DT was validated under varying load conditions. The results demonstrated that the DT could offer an accurate control with acidic variants proportion and yield difference of less than 2% compared to the offline analysis. The embedding mechanistic model also showed a positive predictive performance with an average RMSE of 11.7% during the DT test under >10% sample variation. Practical scenario tests indicated that tightening the control target could further enhance the DT robustness, achieving over 98% success rate with an average yield of 72.7%. The results demonstrated that the constructed DT could accurately mimic real-world situations and perform an automated and flexible pooling in IEC. Additionally, a detailed methodology for applying DT was summarized.

Mild hyperthermia enhanced synergistic uric acid degradation and multiple ROS elimination for an effective acute gout therapy.

BACKGROUND: Acute gouty is caused by the excessive accumulation of Monosodium Urate (MSU) crystals within various parts of the body, which leads to a deterioration of the local microenvironment. This degradation is marked by elevated levels of uric acid (UA), increased reactive oxygen species (ROS) production, hypoxic conditions, an upsurge in pro-inflammatory mediators, and mitochondrial dysfunction. RESULTS: In this study, we developed a multifunctional nanoparticle of polydopamine-platinum (PDA@Pt) to combat acute gout by leveraging mild hyperthermia to synergistically enhance UA degradation and anti-inflammatory effect. Herein, PDA acts as a foundational template that facilitates the growth of a Pt shell on the surface of its nanospheres, leading to the formation of the PDA@Pt nanomedicine. Within this therapeutic agent, the Pt nanoparticle catalyzes the decomposition of UA and actively breaks down endogenous hydrogen peroxide (H2O2) to produce O2, which helps to alleviate hypoxic conditions. Concurrently, the PDA component possesses exceptional capacity for ROS scavenging. Most significantly, Both PDA and Pt shell exhibit absorption in the Near-Infrared-II (NIR-II) region, which not only endow PDA@Pt with superior photothermal conversion efficiency for effective photothermal therapy (PTT) but also substantially enhances the nanomedicine's capacity for UA degradation, O2 production and ROS scavenging enzymatic activities. This photothermally-enhanced approach effectively facilitates the repair of mitochondrial damage and downregulates the NF-κB signaling pathway to inhibit the expression of pro-inflammatory cytokines. CONCLUSIONS: The multifunctional nanomedicine PDA@Pt exhibits exceptional efficacy in UA reduction and anti-inflammatory effects, presenting a promising potential therapeutic strategy for the management of acute gout.

A pH-responsive metal-organic framework for the co-delivery of HIF-2α siRNA and curcumin for enhanced therapy of osteoarthritis.

The occurrence of osteoarthritis (OA) is highly correlated with the reduction of joint lubrication performance, in which persistent excessive inflammation and irreversible destruction of cartilage dominate the mechanism. The inadequate response to monotherapy methods, suboptimal efficacy caused by undesirable bioavailability, short retention, and lack of stimulus-responsiveness, are few unresolved issues. Herein, we report a pH-responsive metal-organic framework (MOF), namely, MIL-101-NH2, for the co-delivery of anti-inflammatory drug curcumin (CCM) and small interfering RNA (siRNA) for hypoxia inducible factor (HIF-2α). CCM and siRNA were loaded via encapsulation and surface coordination ability of MIL-101-NH2. Our vitro tests showed that MIL-101-NH2 protected siRNA from nuclease degradation by lysosomal escape. The pH-responsive MIL-101-NH2 gradually collapsed in an acidic OA microenvironment to release the CCM payloads to down-regulate the level of pro-inflammatory cytokines, and to release the siRNA payloads to cleave the target HIF-2α mRNA for gene-silencing therapy, ultimately exhibiting the synergetic therapeutic efficacy by silencing HIF-2α genes accompanied by inhibiting the inflammation response and cartilage degeneration of OA. The hybrid material reported herein exhibited promising potential performance for OA therapy as supported by both in vitro and in vivo studies and may offer an efficacious therapeutic strategy for OA utilizing MOFs as host materials.

Insight into the spatiotemporal distribution of antibiotic resistance genes in estuarine sediments during long-term ecological restoration.

In this study, we aimed to investigate the long-term spatiotemporal changes in hydrodynamics, antibiotics, nine typical subtypes of antibiotic resistance genes (ARGs), class 1 integron gene (intI1), and microbial communities in the sediments of a semi-enclosed estuary during ecological restoration with four treatment stages (influent (#1), effluent of the biological treatment area (#2), oxic area (#3), and plant treatment area (#4)). Ecological restoration of the estuary reduced common pollutants (nitrogen and phosphorus) in the water, whereas variations in ARGs showed noticeable seasonal and spatial features. The absolute abundance of ARGs at sampling site #2 considerably increased in autumn and winter, while it significantly increased at sampling site #3 in spring and summer. The strong intervention of biological treatment (from #1 to #2) and aerators (from #2 to #3) in the estuary substantially affected the distribution of ARGs and dominant antibiotic-resistant bacteria (ARB). The dominant ARB (Thiobacillus) in estuarine sediments may have low abundance but important dissemination roles. Meanwhile, redundancy and network analysis revealed that the microbial communities and intl1 were key factors related to ARG dissemination, which was affected by spatial and seasonal ecological restoration. A positive correlation between low flow velocity and certain ARGs (tetM, tetW, tetA, sul2, and ermC) was observed, implying that flow optimization should also be considered in future ecological restoration to remediate ARGs. Furthermore, the absolute abundance of ARGs can be utilized as an index to evaluate the removal capacity of ARGs by estuarine restoration.

A Novel Alginate Lyase: Identification, Characterization, and Potential Application in Alginate Trisaccharide Preparation.

Alginate oligosaccharides (AOS) have many biological activities and significant applications in prebiotics, nutritional supplements, and plant growth development. Alginate lyases have unique advantages in the preparation of AOS. However, only a limited number of alginate lyases have been so far reported to have potentials in the preparation of AOS with specific degrees of polymerization. Here, an alginate-degrading strain Pseudoalteromonasarctica M9 was isolated from Sargassum, and five alginate lyases were predicted in its genome. These putative alginate lyases were expressed and their degradation products towards sodium alginate were analyzed. Among them, AlyM2 mainly generated trisaccharides, which accounted for 79.9% in the products. AlyM2 is a PL6 lyase with low sequence identity (≤28.3%) to the characterized alginate lyases and may adopt a distinct catalytic mechanism from the other PL6 alginate lyases based on sequence alignment. AlyM2 is a bifunctional endotype lyase, exhibiting the highest activity at 30 °C, pH 8.0, and 0.5 M NaCl. AlyM2 predominantly produces trisaccharides from homopolymeric M block (PM), homopolymeric G block (PG), or sodium alginate, with a trisaccharide production of 588.4 mg/g from sodium alginate, indicating its promising potential in preparing trisaccharides from these polysaccharides.

Characterization of a Novel Alginate Lyase with Two Alginate Lyase Domains from the Marine Bacterium Vibrio sp. C42.

Alginate is abundant in the cell walls of brown algae. Alginate lyases can degrade alginate, and thus play an important role in the marine carbon cycle and industrial production. Currently, most reported alginate lyases contain only one functional alginate lyase domain. AlyC8 is a putative alginate lyase with two alginate lyase domains (CD1 and CD2) from the marine alginate-degrading strain Vibrio sp. C42. To characterize AlyC8 and its two catalytic domains, AlyC8 and its two catalytic domain-deleted mutants, AlyC8-CD1 and AlyC8-CD2, were expressed in Escherichia coli. All three proteins have noticeable activity toward sodium alginate and exhibit optimal activities at pH 8.0-9.0 and at 30-40 °C, demonstrating that both CD1 and CD2 are functional. However, CD1 and CD2 showed opposite substrate specificity. The differences in substrate specificity and degradation products of alginate between the mutants and AlyC8 demonstrate that CD1 and CD2 can act synergistically to enable AlyC8 to degrade various alginate substrates into smaller oligomeric products. Moreover, kinetic analysis indicated that AlyC8-CD1 plays a major role in the degradation of alginate by AlyC8. These results demonstrate that AlyC8 is a novel alginate lyase with two functional catalytic domains that are synergistic in alginate degradation, which is helpful for a better understanding of alginate lyases and alginate degradation.

Layer-Averaged Water Temperature Sensing in a Lake by Acoustic Tomography with a Focus on the Inversion Stratification Mechanism.

Continuous sensing of water parameters is of great importance to fluid dynamic progress study in oceans, coastal areas and inland waters. The acoustic tomography technique can perform water temperature field measurements horizontally and vertically using sound wave travel information. The layer-averaged water temperature can also be measured with the acoustic tomography method. However, investigations focusing on the stratified mechanism, which consists of stratification form and its influence on inversion error, are seldom performed. In this study, an acoustic tomography experiment was carried out in a reservoir along two vertical slices to observe the layer-averaged water temperature. Specifically, multi-path sound travel information is identified through ray tracing using high-precision topography data obtained via a ship-mounted ADCP during the experiment. Vertical slices between sound stations are divided into different layers to study layer division inversion methods in different preset types. The inversion method is used to calculate the average water temperature and inversion temperature error of every layer. Different layer methods are studied with a comparison of results. The layer division principle studied in this paper can be used for layer-averaged water temperature sensing with multi-path sound transmission information.

Early Molecular Events during Onset of Diapause in Silkworm Eggs Revealed by Transcriptome Analysis.

Diapause is a form of dormancy, and Bombyx mori silkworm embryos are ideal models for studying diapause in insects. However, molecular events in eggs during the onset of diapause remain unclear. In this study, transcriptome analyses were performed on silkworm diapause eggs via RNA sequencing at 20 and 48 h after oviposition. A total of 6402 differentially expressed genes (DEGs) were detected in diapause eggs at 48 h versus that at 20 h after oviposition. Gene ontology enrichment analysis showed that DEGs in diapause eggs at 48 h versus that at 20 h after oviposition were involved in ribosome-related metabolism and hydrogen transport. Kyoto Encyclopedia of Genes and Genomes analysis revealed several significantly enriched biological pathways, namely the oxidative phosphorylation, Forkhead box protein O3 (FoxO) signaling, ribosome, endoplasmic reticular protein processing, and autophagy pathways. Fifteen DEGs from the FoxO signaling pathway were selected, and their expression profiles were consistent with the transcriptome results from real-time quantitative reverse transcription polymerase chain reaction. Our results can improve understanding of the diapause mechanism in silkworm eggs and identified key pathways for future studies.

Marinomonas algicola sp. nov. and Marinomonas colpomeniae sp. nov., isolated from marine macroalgae.

Two Gram-stain-negative, aerobic, rod-shaped bacteria, polar flagellated, designated strains SM2066T and SM1966T, were respectively isolated from the surfaces of Colpomenia sinuosa and Ulva pertusa macroalgae collected off the coastal areas of Rongcheng, PR China. Strain SM2066T grew at 8-37 °C and with 0.5-7.0 % (w/v) NaCl, while strain SM1966T grew at 5-30 °C and with 0.5-8.5% (w/v) NaCl. Both of them reduced nitrate to nitrite and required Na+ for growth but neither of them hydrolysed starch and DNA. Phylogenetic analysis based on 16S rRNA gene and single-copy orthologous cluster sequences revealed that both strains SM2066T and SM1966T were affiliated with the genus Marinomonas but formed distinct phylogenetic branches from known Marinomonas species, respectively sharing the highest 16S rRNA gene sequence similarities with type strains of Marinomonas ushuaiensis (97.9 %) and Marinomonas blandensis (96.7 %). The digital DNA-DNA hybridization and average nucleotide identity values between strains SM2066T and SM1966T and type strains of closely related Marinomonas species were all below 22.9 and 79.9 mol%, respectively. The major fatty acids of the two strains were summed feature 3 (C16 : 1 ω6c/C16 : 1 ω7c), summed feature 8 (C18 : 1 ω7c) and C16 : 0, with their predominant polar lipids being phosphatidylethanolamine and phosphatidylglycerol, and their sole respiratory quinone being Q-8. The genomic DNA G+C contents of strains SM2066T and SM1966T determined from genomic sequences were 40.3 and 41.6 mol%, respectively. On the basis of the polyphasic evidence presented in this study, strains SM2066T and SM1966T are considered to represent two novel species within the genus Marinomonas, for which the names Marinomonas colpomeniae sp. nov. and Marinomonas algicola sp. nov. are proposed. The type strains are SM2066T (=MCCC 1K04390T= KCTC 82372T) and SM1966T (=MCCC 1K04387T= KCTC 72848T), respectively.

[Development of Motion Unit of Simulated Intelligent Endotracheal Suctioning Robot].

A motion unit for sucking robot with a stable motion, convenient operation and process simulation is introduced. The key parameters and process data of the sucking operation were obtained from the clinical work, which provided the basis for the design of the sucking robot motion unit. According to the points of sucking action, robotic thumb, forefinger and metacarpophalangeal joints were used to grip the suction tube, and the servo and arm structure were used to simulate the motion of the wrist and elbow to complete the rotation and push of the sputum suction tube. The feasibility is verified through the advanced sputum suction training model. The movement unit is stable in movement, and can smoothly complete the clamping, feeding, back off protection and rotating tube removal of the sputum suction tube, so as to achieve effective sputum suction.

Perfusion Computer Tomography Assessment of the Effect of Angiotensin II On Blood Flow Distribution in Rabbits with Intrarenal VX2 Tumors.

BACKGROUND/AIMS: Unlike other organs, which only have one set of capillary network, the renal microvasculature consists of two sets of capillary network series connected by efferent arterioles. Angiotensin II constricts the efferent glomerular artery. Hence, renal tumor blood flow (BF) distribution may be different from tumors in other organs. This study aims to investigate the effects of angiotensin II on the hemodynamics of intrarenal VX2 tumors using perfusion computed tomography(CT). METHODS: Twenty-four male New Zealand white rabbits were randomly divided into three groups: groups A (blank controls), group B (negative controls), and group C (angiotensin II-treated animals). Group B and C were established to the model of intrarenal VX2 tumors. Furthermore, perfusion CT of the kidney was performed in each group. Prior to perfusion CT scan in group C, the mean arterial blood was elevated to 150-160 mmHg by angiotensin II. The BF, blood volume (BV), mean transit time (MTT), capillary permeability-surface area product (PS), and relative permeability-surface area product (RPS) of tumors and renal tissues were calculated. RESULTS: Compared with normal renal cortex tissues in group A, the BF, BV and PS values of tumors in group B were significantly lower, MTT was prolonged and RPS increased. Compared with group B, only the RPS of these tumors increased from 83.23 ± 29.17% to 120.94 ± 31.84% by angiotensin II infusion. Angiotensin II significantly increased the RPS value of the renal cortex distant from the tumor (CDT) and the right renal cortex (RRC). CONCLUSIONS: Perfusion CT can accurately observe the influence of angiotensin II on normal and tumor BF in kidneys. This clarifies the effect of angiotensin II on intrarenal tumor hemodynamics.

Etiology of community-acquired pneumonia in 1500 hospitalized children.

Childhood community-acquired pneumonia (CAP) is a common illness; however, comprehensive studies of hospitalizations for CAP among children in China based on prospective and multicenter data collection are limited. The aim of this investigation was to determine the respiratory pathogens responsible for CAP in hospitalized children. From January to December 2015, oropharyngeal swabs and blood serum were collected from hospitalized children with CAP symptoms ranging in age from 6 months to 14 years at 10 hospitals across China. We used immunofluorescence to detect antibodies for eight respiratory viruses and passive agglutination to detect specific IgM against Mycoplasma pneumoniae (M. pneumoniae). Of 1500 children presenting with CAP, 691 (46.1%) tested positive for at least one pathogen (virus or M. pneumoniae). M. pneumoniae (32.4%) was detected most frequently, followed by respiratory syncytial virus (11.5%), adenovirus (5.0%), influenza A virus (4.1 %), influenza B virus (3.4%), parainfluenza virus types 2 and 3 type (3.1 %), parainfluenza virus type 1 (2.9%), and human metapneumovirus (0.3%). Co-infections were identified in 128 (18.5%) of the 691 cases. These data provide a better understanding of viral etiology and M. pneumoniae in CAP in children between 6 months and 14 years in China. More study of the etiologic investigations that would further aid the management of pneumonia is required. With effective immunization for RSV, ADV, and M. pneumoniae infections, more than one-half of the pneumonia cases in this study could have been prevented.

[Development of Diagrammatic Recording System for Choledochoscope and Its Clinical Application].

OBJECTIVES: To develop a diagrammatic recording system for choledochoscopy and evaluate the system with clinical application. METHODS: To match the real-time image and procedure illustration during choledochoscopy examination, we combined video-image capture and speech recognition technology to quickly generate personalized choledochoscopy images and texts records. The new system could be used in sharing territorial electronic medical records, telecommuting, scientific research and education, et al. RESULTS: In the clinical application of 32 patients, the choledochoscopy diagrammatic recording system could significantly improve the surgeons' working efficiency and patients' satisfaction. It could also meet the design requirement of remote information interaction. CONCLUSIONS: The choledochoscopy diagrammatic recording system which is recommended could elevate the quality of medical service and promote academic exchange and training.

Shifts in Rumen Fermentation and Microbiota Are Associated with Dissolved Ruminal Hydrogen Concentrations in Lactating Dairy Cows Fed Different Types of Carbohydrates.

BACKGROUND: Different carbohydrates ingested greatly influence rumen fermentation and microbiota and gaseous methane emissions. Dissolved hydrogen concentration is related to rumen fermentation and methane production. OBJECTIVES: We tested the hypothesis that carbohydrates ingested greatly alter the rumen environment in dairy cows, and that dissolved hydrogen concentration is associated with these changes in rumen fermentation and microbiota. METHODS: Twenty-eight lactating Chinese Holstein dairy cows [aged 4-5 y, body weight 480 ± 37 kg (mean ± SD)] were used in a randomized complete block design to investigate effects of 4 diets differing in forage content (45% compared with 35%) and source (rice straw compared with a mixture of rice straw and corn silage) on feed intake, rumen fermentation, and microbial populations. RESULTS: Feed intake (10.7-12.6 kg/d) and fiber degradation (0.584-0.692) greatly differed (P ≤ 0.05) between cows fed the 4 diets, leading to large differences (P ≤ 0.05) in gaseous methane yield (27.2-37.3 g/kg organic matter digested), dissolved hydrogen (0.258-1.64 µmol/L), rumen fermentation products, and microbiota. Ruminal dissolved hydrogen was negatively correlated (r < -0.40; P < 0.05) with molar proportion of acetate, numbers of fungi, abundance of Fibrobacter succinogenes, and methane yield, but positively correlated (r > 0.40; P < 0.05) with molar proportions of propionate and n-butyrate, numbers of methanogens, and abundance of Selenomonas ruminantium and Prevotella spp. Ruminal dissolved hydrogen was positively correlated (r = 0.93; P < 0.001) with Gibbs free energy changes of reactions producing greater acetate and hydrogen, but not correlated with those reactions producing more propionate without hydrogen. CONCLUSIONS: Changes in fermentation pathways from acetate toward propionate production and in microbiota from fibrolytic toward amylolytic species were closely associated with ruminal dissolved hydrogen in lactating dairy cows. An unresolved paradox was that greater dissolved hydrogen was associated with greater numbers of methanogens but with lower gaseous methane emissions.

Time-resolved fluorescence spectroscopy study of excited state dynamics of alkyl- and benzo-substituted triphyrin(2.1.1).

We have investigated the photophysical properties of alkyl-substituted triphyrin(2.1.1) (ATp) and benzotriphyrin(2.1.1) (BTp) by steady-state and time-resolved fluorescence spectroscopy. We focused on the effect of NH proton tautomerization, planarity of the macrocycles, and substituents on these properties. The fluorescence quantum yields (Φy) of ATp did not depend on solvent viscosity, whereas those of BTp increased with solvent viscosity, reaching a maximum value of 0.17 in paraffin. Interestingly, analyzing Φy showed that the non-radiative rate constant of BTp decreased sharply as the solvent viscosity increased. These results suggest that the substituted phenyl groups play a crucial role in suppressing molecular distortion, thus leading to decreased non-radiative relaxation in triphyrin(2.1.1). The hydrogen bond formed in the inner cavity potentially contributes to the suppression of the structural distortion, whereas the pyrrole rings in the macrocycle are close, as in porphycene.