Analytical model for power dissipation in cell membranes in suspensions exposed to electric fields

Due to interaction among cells, it is too complex to build an exactanalytical model for the power dissipation within the cell membrane in suspensions exposed toexternal fields. An approximate equivalence method is proposed to resolve this problem. Based on theeffective medium theory, the transmembrane voltage on cells in suspensions was investigated by theequivalence principle. Then the electric field in the cell membrane was determined. Finally,analytical solutions for the power dissipation within the cell membrane in suspensions exposed toexternal fields were derived according to the Joule principle. The equations show that theconductive power dissipation is predominant within the cell membrane in suspensions exposed todirect current or lower frequencies, and dielectric power dissipation prevails at high frequenciesexceeding the relaxation frequency of the exposed membrane.

UV/Vis-based process analytical technology to improve monoclonal antibody and host cell protein separation

Process analytical technology(PAT) is gaining more interest in the biomanufacturing industry because of its potential to improve operational control and compliance through real-time quality assurance.Currently, biopharmaceutical producers mainly monitor chromatographic processes with ultraviolet/visible(UV/Vis) absorbance. However, this measurement has a very limited correlation with purity and quantity. The current study aims to determine the concentration of monoclonal antibody(mAb) and host cell proteins(HCPs) using a build-in UV/Vis monitoring during Protein A affinity chromatography and to optimize the separation conditions for high purity of mAb and minimizing the HCPs content. The eluate was analyzed through in-line UV/Vis at 280 and 410 nm, representing mAb and HCPs concentration,respectively. Each 0.1 column volume(CV) fraction of UV/Vis chromatogram peak area were calculated,and different separation conditions were then compared. The optimum conditions of mAb separation were found as 12 CV loading, elution at pH 3.5, and starting the collection at 0.5 CV point, resulting in high m Ab recovery of 95.92% and additional removal of 49.98% of HCP comparing with whole elution pool. This study concluded that UV/Vis-based in-line monitoring at 280 and 410 nm showed a high potential to optimize and real-time control Protein A affinity chromatography for mAb purification from HCPs.

Feasibility Assessment of Fast Numerical Simulations for Real-Time Monitoring and Control of PEM Fuel Cells

Computational models that ensure accurate and fast responses to the variations in operating conditions,such as the cell tem-perature and relative humidity(RH),are essential monitoring tools for the real-time control of proton exchange membrane(PEM)fuel cells.To this end,fast cell-area-averaged numerical simulations are developed and verifi ed against the present experiments under various RH levels.The present simulations and measurements are found to agree well based on the cell voltage(polarization curve)and power density under variable RH conditions(RH=40%,RH=70%,and RH=100%),which verifi es the model accuracy in predicting PEM fuel cell performance.In addition,computationally feasible reduced-order models are found to deliver a fast output dataset to evaluate the charge/heat/mass transfer phenomena as well as water production and two-phase fl ow transport.Such fast and accurate evaluations of the overall fuel cell operation can be used to inform the real-time control systems that allow for the improved optimization of PEM fuel cell performance.

Real-time observation of integrin bending/unbending conformational changes on living cells

Introduction Integrins are a large family of adhesion molecules broadly expressed on the surface of a wide variety of cells as heterodimers. Binding of integrins to ligands provides not only mechanical anchorage for the cell to another cell or

Analytical quality-by-design approach for sample treatment of BSA-containing solutions

The sample preparation of samples conlaining bovine serum albumin（BSA）,e.g..as used in transdermal Franz diffusion cell（FDC） solutions,was evaluated using an analytical qualily-by-design（QbD）approach.Traditional precipitation of BSA by adding an equal volume of organic solvent,often successfully used with conventional HPLC-PDA,was found insufficiently robust when novel fused-core HPLC and/or UPLC-MS methods were used.In this study,three factors（acetonitrile（%）.formic acid（%） and boiling time（min）） were included in the experimental design to determine an optimal and more suitable sample treatment of BSAcontaining FDC solutions.Using a QbD and Derringer desirability（D） approach,combining BSA loss,dilution factor and variability,we constructed an optimal working space with the edge of failure defined as D〈0.9.The design space is modelled and is confirmed to have an ACN range of 83 ± 3% and FA content of 1 ±0.25%.

Prediction of the Biaxial Failure Strength of Composite Laminates with Unit Cell Analytic Model

A new method to predict the ultimate strength of fiber reinforced composites under arbitrary load condition is introduced. The micromechanics strength theory is used to perform the final failure prediction of composite laminates. The theory is based on unit cell analytic model which can provide the ply composite material properties by only using the constituent fiber and matrix properties and the laminate geometric parameters without knowing any experimental information of the laminates. To show that this method is suitable for predicting the strength of composite laminates, the micromechanics strength theory is ranked by comparing it with all the micro-level and the best two macro-level theories chosen from the World Wide Failure Exercise. The results show that this method can be used for predicting strength of any composite laminates and provide a direct reference for composite optimum design.

Detection of influenza A virus RNA in birds by optimized Real-Time PCR system

Objective:To evaluate the use of Real-Time PCR system based on specific amplification of matrix protein gene fragment for influenza A virus RNA detection in cloacal swabs from wild birds.Methods:Sensitivity,specificity and reproducibility of analysis results were identified. Study of cloacal swabs from wild birds for influenza A virus presence was performed.Results: Reproducibility of low concentrations of virus detection in samples by Real-Time PCR was significantly higher than that of detection based on cytopathic effect of viruses grown on MDCK cell culture.Conclusions:Real-Time PCR system for influenza A virus RNA detection is developed and applied for virus surveillance study.

Employing a Backpropagation Neural Network for Predicting Fear of Cancer Recurrence among Non-Small Cell Lung Cancer Patients

Objective:Non-small cell lung cancer(NSCLC)patients often experience significant fear of recurrence.To facilitate precise identification and appropriate management of this fear,this study aimed to compare the efficacy and accuracy of a Backpropagation Neural Network(BPNN)against logistic regression in modeling fear of cancer recurrence prediction.Methods:Data from 596 NSCLC patients,collected between September 2023 and December 2023 at the Cancer Hospital of the Chinese Academy of Medical Sciences,were analyzed.Nine clinically and statistically significant variables,identified via univariate logistic regression,were inputted into both BPNN and logistic regression models developed on a training set(N=427)and validated on an independent set(N=169).Model performances were assessed using Area Under the Receiver Operating Characteristic(ROC)Curve and Decision Curve Analysis(DCA)in both sets.Results:The BPNN model,incorporating nine selected variables,demonstrated superior performance over logistic regression in the training set(AUC=0.842 vs.0.711,p<0.001)and validation set(0.7 vs.0.675,p<0.001).Conclusion:The BPNN model outperforms logistic regression in accurately predicting fear of cancer recurrence in NSCLC patients,offering an advanced approach for fear assessment.

Changes of the Transcriptional Levels of Molecules Associated with Endogenous Antigen Processing and Presentation in Porcine Skin-derived Dendritic Cells Infected with PCV2 in vivo

[Objective] This study aimed to investigate the changes of the transcriptional levels of molecules associated with endogenous antigen processing and presenta- tion in porcine skin-derived dendritic cells infected with PCV2 in vivo. [Method] Healthy 40-day-old Landrace piglets were infected with porcine circovirus type 2 （PCV2） and euthanized on the 34, 7rd, 14th, 21st and 35th d post inoculation （DPI）. The porcine skin-derived dendritic cells （DCs） were collected to analyze the transcrip- tional levels of molecules （LMP7, UBP, MHC-I, calreticulin） associated with endogenous antigen processing and presentation by using real-time fluorescent quantitative PCR （real-time FQ-PCR）. [Result] The results showed that the level of LMP7 mR- NAs was reduced significantly on the 3DPI （P〈0.05）; the level of UBP mRNAs was consistently up-regulated, which increased significantly on the 21DPI and 35DPI （P〈 0.05）; the level of MHC-I mRNAs was significantly down-regulated on the 7DPI （P〈 0.05）; the level of calreticulin mRNAs was up-regulated slightly without significant dif- ference. [Conclusion] PCV2 can inhibit the endogenous antigen processing and presentation ability of porcine skin-derived DCs at early stages of infection.

Involvement of interstitial cells of Cajal in experimental severe acute pancreatitis in rats

AIM:To observe the changes in interstitial cells of Cajal(ICC) in rats with experimental severe acute pancreatitis(SAP).METHODS:A total of twenty-four SD rats were randomly divided into two groups(n = 12),namely the sham(S) group and the SAP group;the SAP rat model was established by retrograde injection of 5% sodium taurocholate(1.0 mL/kg) into the pancreatic duct.Twenty-four hours later intestinal motility was assessed by testing small intestinal propulsion rate,and then the rats were sacrificed.The pancreas and jejunum were resected and underwent routine pathologic examination.Immunohistochemical staining was used to detect c-kit-positive cells in the jejunum.Expression of c-kit mRNA was detected by real-time polymerase chain reaction,and the expression of c-kit protein was evaluated by Western blotting.Ultrastructure of ICC was evaluated by transmission electron microscopy.RESULTS:There was bleeding,necrosis and a largeamount of inflammatory cell infiltration in pancreatic tissue in the SAP group,while in jejunal tissue we observed a markedly denuded mucosal layer,loss of villous tissue and a slightly dilated muscular layer.The small intestinal propulsion rate was 68.66% ± 2.66% in the S group and 41.55% ± 3.85% in the SAP group.Compared with the S group,the rate of the SAP group decreased sharply.The density of c-kit-positive cells in the SAP group was significantly lower than in the S group;the respective mean densities were 88.47 ± 10.49 in the S group and 56.11 ± 7.09 in the SAP group.The levels of c-kit protein and mRNA were 0.36 ± 0.04 and 1.29 ± 0.91 in the SAP group,respectively,which were significantly lower than those in the S group(0.53 ± 0.06,0.64 ± 0.33,respectively).In the SAP group,ICC profiles showed the same change tendency,such as vacuolation of mitochondria,irregular vacuoles and loosened desmosome-like junctions.CONCLUSION:Decreased c-kit-positive cells and ultrastructural changes in ICC resulting from blockade of the c-kit signaling pathway are involved in the intestinal dysmotility associated with SAP.

Association between Bmi1 and clinicopathological status of esophageal squamous cell carcinoma

AIM： To investigate the clinicopathological roles of Bmil in esophageal squamous cell carcinoma （ESCC）.METHODS： Quantitative real-time polymerase chain reaction and immunohistochemical staining for Broil were performed in cancerous and adjacent non-cancerous paraffin-embedded esophageal specimens.RESULTS： The Bmil expression level was unaffected by gender and age. The level of Broil mRNA in ESCC was significantly higher than that in the adjacent non-cancerous tissues （2.181 ± 2.158 vs 0.931 ± 0.894, P = 0.0152）, and its over-expression was aggressively associated with lymph node metastasis （3.580 ± 2.487 vs 1.703 ± 0.758, P = 0.0003）, poorer cell differentiation （P = 0.0000） and advanced pathological stage （3.827± 2.673 vs 1.590 ± 0.735, P = 0.0001）. The patients were divided into high-expression and low-expression groups based on the median expression level of Bmi1 mRNA, and a shorter overall survival time in the former group was observed. Immunohistochemistry for Bmi1 oncoprotein showed diffusely positive, focally positive and negative expression in 44, 16 and 10 of 70 ESCC cases, respectively, compared with three, two and five of 10 adjacent non-cancerous cases （P = 0.027）. The positive rate of the oncoprotein in samples of histological grade Ⅲ was higher than that of grade Ⅱ（P = 0.031）, but its expression had no relation to the lymph node metastasis and pathological staging. In 70 ESCC samples, Bmi1 showed high intense expression in the cytoplasm and less or even no expression in the nucleus.CONCLUSION： Bmi1 was over-expressed in ESCC. Increased Bmi1 mRNA expression was significantly associated with ESCC progression, and the oncoprotein was largely distributed in the cytoplasm of tumor cells.

Expression of OCT4 in human esophageal squamous cell carcinoma is significantly associated with poorer prognosis

AIM： To explore the expression pattern of OCT4 in hu- man esophageal squamous cell carcinoma and its sig- nificance in diagnosis and prognosis.

Real-time trajectory optimization for powered planetary landings based on analytical shooting equations

Traditionally,numerical trajectory integration for shooting equation calculation and iterations for shooting with randomly guessed initial solutions deteriorate the real-time performance of indirect methods for on-board applications.In this study,the indirect method is improved to achieve real-time trajectory optimization of fuel-optimal powered planetary landings with the help of analytical shooting equation derivations and a practical homotopy technique.Specifically,the contributions of this paper are threefold.First,the analytical expressions for shooting equation calculation are derived to replace the traditional time-consuming trajectory integration.Consequently,the computational efficiency is significantly improved.Second,the original three-dimensional landing problem is connected with a simplified one-dimensional problem that only involves the vertical dynamics,and its analytical solution is obtained based on Pontryagin’s minimum principle.Third,starting with the analytical solution,the accurate solution of the original landing problem can be obtained through an adaptive homotopy process.Simulation results of Earth landing scenarios are given to substantiate the effectiveness of the proposed techniques and illustrate that the developed method can obtain a fuel-optimal landing trajectory in 5 ms with 100%success rate.

Recent Progress in Interfacial Dipole Engineering for Perovskite Solar Cells

Design and modification of interfaces have been the main strategies in developing perovskite solar cells(PSCs). Among the interfacial treatments, dipole molecules have emerged as a practical approach to improve the efficiency and stability of PSCs due to their unique and versatile abilities to control the interfacial properties. Despite extensive applications in conventional semiconductors, working principles and design of interfacial dipoles in the performance/stability enhancement of PSCs are lacking an insightful elucidation. In this review, we first discuss the fundamental properties of electric dipoles and the specific roles of interfacial dipoles in PSCs. Then we systematically summarize the recent progress of dipole materials in several key interfaces to achieve efficient and stable PSCs. In addition to such discussions, we also dive into reliable analytical techniques to support the characterization of interfacial dipoles in PSCs. Finally, we highlight future directions and potential avenues for research in the development of dipolar materials through tailored molecular designs. Our review sheds light on the importance of continued efforts in this exciting emerging field, which holds great potential for the development of high-performance and stable PSCs as commercially demanded.

Effects of processing pH stimulation on cooperative bioleaching of chalcopyrite concentrate by free and attached cells

In order to investigate the effects of processing pH stimulation on bioleaching of chalcopyrite by moderate thermophiles,copper leaching rates and the dynamics of microbial community structures of free and attached cells were monitored. The results indicated that when the processing pH values were respectively adjusted to 1.0 and 3.0 on day 14, both free and attached cells experienced an adaptive phase. Meanwhile, the copper leaching rates were 86.9% and 64.0%,respectively, as opposed to a copper leaching rate of 87.5% in the control group without pH stimulation. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis suggested that pH stimulation imposed less impact on the attached organisms than on the free cells, indicating that the attached cells were more resistant to processing pH stimulation than the free cells. Furthermore, adjusting processing pH to 3.0 significantly disrupted both free and attached microbial communities, and the bioleaching system could not recover to the normal status as the control group.

Role of miR-124 in the regulation of retinoic acid-induced Neuro-2A cell differentiation

Retinoic acid can cause many types of cells,including mouse neuroblastoma Neuro-2 A cells,to differentiate into neurons.However,it is still unknown whether microRNAs(miRNAs)play a role in this neuronal differentiation.To address this issue,real-time polymerase chain reaction assays were used to detect the expression of several differentiation-related miRNAs during the differentiation of retinoic acid-treated Neuro-2 A cells.The results revealed that miR-124 and miR-9 were upregulated,while miR-125 b was downregulated in retinoic acid-treated Neuro-2 A cells.To identify the miRNA that may play a key role,miR-124 expression was regulated by transfection of miRNA mimics or inhibitors.Morphological analysis results showed that inhibition of miR-124 expression reversed the effects of retinoic acid on neurite outgrowth.Moreover,miR-124 overexpression alone caused Neuro-2 A cells to differentiate into neurons,and its inhibitor could block this effect.These results suggest that miR-124 plays an important role in retinoic acid-induced differentiation of Neuro-2 A cells.

Novel esophageal squamous cell carcinoma bone metastatic clone isolated by scintigraphy, X ray and micro PET/CT

AIM: To establish a Chinese esophageal squamous cell carcinoma (ESCC) cell line with high bone metastasis potency using 99mTc-methylene diphosphonate (99mTc-MDP) micro-pinhole scintigraphy, X ray and micro-positron emission tomography/computed tomography (PET/CT) for exploring the mechanism of occurrence and development in esophageal cancer.

Dorsal root ganglion neurons promote proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells

Preliminary animal experiments have confirmed that sensory nerve fibers promote osteoblast differentiation, but motor nerve fibers have no promotion effect. Whether sensory neurons pro- mote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells remains unclear. No results at the cellular level have been reported. In this study, dorsal root ganglion neurons （sensory neurons） from Sprague-Dawley fetal rats were co-cultured with bone marrow mesenchymal stem cells transfected with green fluorescent protein 3 weeks after osteo- genic differentiation in vitro, while osteoblasts derived from bone marrow mesenchymal stem cells served as the control group. The rat dorsal root ganglion neurons promoted the prolifera- tion of bone marrow mesenchymal stem cell-derived osteoblasts at B and 5 days of co-culture, as observed by fluorescence microscopy. The levels of mRNAs for osteogenic differentiation-re- lated factors （including alkaline phosphatase, osteocalcin, osteopontin and bone morphogenetic protein 2） in the co-culture group were higher than those in the control group, as detected by real-time quantitative PCR. Our findings indicate that dorsal root ganglion neurons promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells, which pro- vides a theoretical basis for in vitro experiments aimed at constructing tissue-engineered bone.

Serum miR-339-3p as a potential diagnostic marker for non-small cell lung cancer

Objective:MicroRNA(miRNA),a short noncoding RNA,is claimed to be a potential blood-based biomarker.We aimed to identify and evaluate miRNAs as diagnostic biomarkers for non-small cell lung cancer(NSCLC).Methods:Profiles of 745 miRNAs were screened in the serum of 8 patients with NSCLC and 8 age-and sex-matched controls using TaqMan low-density arrays(TLDAs)and validated in 25 patients with NSCLC and 30 with other lung diseases(OLs)as well as in 19 healthy persons(HPs).The diagnostic performance of the candidate miRNAs was assessed in 117 cases of NSCLC and 113 OLs using quantitative real-time polymerase chain reaction(qRT-PCR).Differences in miRNA expression between patients with NSCLC and controls were assessed using the Mann–Whitney U test.The area under receiver operating characteristic(ROC)curve(AUC)was obtained based on the logistic regression model.Results:Ten miRNAs were found to be differentialy expressed between patients with NSCLC and controls,including miR-769,miR-339-3p,miR-339-5p,miR-519a,miR-1238,miR-99a#,miR-134,miR-604,miR-539,and miR-342.The expression of miR-339-3p was significantly higher in patients with NSCLC than in those with OLs(P<0.001)and HPs(P=0.020).ROC analysis revealed an miR-339-3p expression AUC of 0.616[95%confidence interval(CI):0.561–0.702].The diagnostic prediction was increased(AUC=0.706,95%CI:0.649–0.779)in the model combining miR-339-3p expression and other known risk factors(i.e.,age,smoking status,and drinking status).Conclusions:MiR-339-3p was significantly upregulated in patients with NSCLC compared with participants without cancer,suggesting a diagnostic prediction value for high-risk individuals.Therefore,miR-339-3p expression could be a potential blood-based biomarker for NSCLC.

Aression of TLR_9 in human pulmonary adenocarcinoma cell line A549

Objective:Being considered as a bridge between the innate immunity and acquired immunity,Toll-like receptors(TRLs) are very important innate immunity moleculars.Recent researchs on the innate immunity have focused on the relationship between TLRs and human tumor.This paper investgated the expression and significance of TLR9 in human pulmonary adenocarcinoma cell(A549 cell) and human bronchial epithelial cell(HBE cell).Methods:After culturing A549 cell and HBE cell in vitro,the expression of TLR9 mRNA and protein in both cells were detected by immunocytochemistry,Real-time Quantitative Reverse Transcriptase-Polymerase Chain Reaction(Real-time Quantitative PCR) and Western blot,respectively.Results:By immunocytochemistry staining,TLR9 was mainly expressed in both cells' cell membrane and endochylema as brown-yellow material.It showed that the expressions of TLR9 mRNA and protein in A549 cell were stronger than those in HBE cell(P < 0.01).Conclusion:The results suggest TLR9 might cause the progression of human pulmonary adenocarcinoma,and the mechanism needs to be further investgatied.