Search

Guiling Li,1 Li Wang,2 Heguang Zhang,1 Ying Luan,1 Qi Sun,1 Libo Duo1 1Department of Clinical Laboratory, the Second Hospital Affiliated to Harbin Medical University, Harbin, Heilongjiang, 150086, People’s Republic of China; 2Department of Clinical Laboratory, School of Medicine, Chengdu Women’s and Children’s Central Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, 611731, People’s Republic of ChinaCorrespondence: Libo Duo, Department of Clinical Laboratory, the Second Hospital affiliated to Harbin Medical University, No. 246 XueFu Road, NanGang District, Harbin, Heilongjiang, 150086, People’s Republic of China, Tel +86 045186605382, Email duolibo@163.comObjective: In this study, we constructed ampG knock-out and knock-in strains from a clinically isolated Kp1strain carrying ampR-ampC in its plasmid and compared them with the Kp NTUH-K2044 strain to investigate the relationship between ampG and ampR-ampC-induced expression.Methods: We created the ampG gene deletion mutant strains Kp1-ΔampG and Kp NTUH-K2044-ΔampG with pKO3-km plasmid using homologous recombination technology. We constructed the Kp NTUH-K2044-RC and Kp NTUH-K2044-ΔampG-RC drug resistance model strains with plasmid pACYC184. We constructed the ampG knock-in strains by introducing the ampG genes of Kp1, Enterobacter cloacae 029M, Pseudomonas aeruginosa PAO1, Escherichia coli ATCC25922, and Salmonella typhimurium LT2 into the ampG gene-deleted strains with carrier pet-30a. Real-time polymerase chain reaction (real-time PCR) was used to detect the relative expressions of ampC and ampG mRNAs.Results: Compared with Kp1, the induction phenotype of the ampC of Kp1-ΔampG strain disappeared, the ampC expression was reduced, and the minimal inhibitory concentration (MIC) values of cefoxitin and ceftazidime significant decrease from 128 μg/mL to 1 μg/mL. Based on Kp1, five strain were successfully constructed to complement the ampG genes from five knock-in strain, and all of the above complemented strains showed inducible expression of ampC and restored the expression of ampG to varying degrees, as well as restored resistance to the antimicrobial drugs cefoxitin and ceftazidime (P < 0.05). The ampC and ampG genes were barely expressed in Kp NTUH-K2044-ΔampG-RC when compared with Kp NTUH-K2044-RC. The expressions of ampG and ampC in each knock-in strain were recovered, the induction phenotype of ampC was restored, and the MIC values of cefoxitin and ceftazidime were increased. (P < 0.05).Conclusion: In this study, we found that ampG was an essential regulator for the plasmid-mediated ampC-induced expression in K. pneumoniae.Keywords: ampC inducible expression, AmpG regulator, gene knockout, gene knock-in, Klebsiella pneumoniae

Xinye Song,1,&ast; Mengxiao Luan,2,&ast; Weiyi Zhang,1 Ruizheng Zhang,1 Li Xue,1 Yong Luan1 1Department of Anesthesiology, the First Affiliated Hospital of Dalian Medical University, Dalian, 116011, People’s Republic of China; 2Department of Biomedical Engineering, Tsinghua University, Beijing, 100084, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Yong Luan, Email luanyong@dmu.edu.cnIntroduction: The restricted duration is a fundamental drawback of traditional local anesthetics during postoperative pain from a single injection. Therefore, an injectable local anesthetic that produces repeatable on-demand nerve blocks would be ideal.Methods: We offer ultrasound-triggered on-demand analgesia consisting of dendritic mesoporous silica nanoparticles (DMSN) carried with ultrasound-sensitive perfluoropentane (PFP) and levobupivacaine (DMSN-bupi-PFP) to achieve repeatable and customizable on-demand local anesthetics.Results: The vaporization of liquid PFP was triggered by ultrasound irradiation to produce a gas environment. Subsequently, the enhanced cavitation effect could improve the release of levobupivacaine to achieve pain relief under a moderate-intensity ultrasound irradiation. DMSN-bupi-PFP demonstrated a controlled-release pattern and showed a reinforced ultrasonic sensitivity compared to levobupivacaine loaded DMSN (DMSN-bupi). The sustained release of levobupivacaine produced continuous analgesia of more than 9 hours in a model of incision pain, approximately 3 times longer than a single free levobupivacaine injection (3 hours). The external ultrasound irradiation can trigger the release of levobupivacaine repeatedly, resulting in on-demand analgesia. In addition, DMSN-bupi-PFP nanoplatforms for ultrasound-enabled analgesia showed low neurotoxicity and good biocompatibility in vitro and in vivo.Conclusion: This DMSN-bupi-PFP nanoplatform can be used in pain management by providing long-lasting and on-demand pain alleviation with the help of moderate-intensity ultrasound.Keywords: moderate-intensity ultrasound, phase-transitional, analgesia, nanomedicine

Yue Jiang,1 Chunzhi Huang,1,2 Yuxia Luan1 1Department of Pharmaceutics, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong Province, People’s Republic of China; 2Department of Pharmacy, Third Affiliated Hospital of Zhengzhou University, Zhengzhou, People’s Republic of ChinaCorrespondence: Yuxia LuanDepartment of Pharmaceutics, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, 44 Wenhuaxi Road, Jinan, Shandong Province 250012, People’s Republic of ChinaTel +86 531-88382007Fax +86 531-88382548Email yuxialuan@sdu.edu.cnIntroduction: Synergistic treatment integrating photothermal therapy (PTT) and chemotherapy is a promising strategy for hepatocellular carcinoma (HCC). However, the most commonly used photothermal agent, IR820, and chemotherapeutic drug, doxorubicin hydrochloride (DOX), are both hydrophilic molecules that suffer from the drawbacks of a short circulation time, rapid elimination and off-target effects.Methods and Results: Herein, a novel nanodrug that combined HCC-targeted IR820 and DOX was developed based on excipient-free co-assembly. First, lactosylated IR820 (LA-IR820) was designed to target HCC. Then, the LA-IR820/DOX nanodrug (LA-IR820/DOX ND) was purely self-assembled without excipient assistance. The physicochemical properties and the chemo-photothermal antitumour activity of the excipient-free LA-IR820/DOX ND were evaluated. More importantly, the obtained LA-IR820/DOX ND exhibited 100% drug loading, remarkable HCC targeting and excellent antitumour efficacy.Conclusion: This excipient-free LA-IR820/DOX ND may be a promising candidate for the synchronous delivery and synergistic targeting of IR820 and DOX as a combined chemo-photothermal therapy.Keywords: excipient-free, hepatoma cell targeting, self-assembly nanodrug, photothermal therapy, chemotherapy

Junhao Yan,1 Xinling Ding,2 Lili Xiong,3 E Liu,1 Yixuan Zhang,1 Yingjie Luan,1 Lihua Qin,1 Changman Zhou,1 Weiguang Zhang1 1Department of Anatomy and Histology, School of Basic Medical Sciences, Peking University, Beijing 100191, People’s Republic of China; 2Department of Anatomy, Chifeng Medical College, Neimenggu 024000, People’s Republic of China; 3Department of Anatomy, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu 610041, People’s Republic of China Objectives: In this study, the effects of team-based learning (TBL) method on the anatomy course for students in People’s Republic of China were assessed. Methods: The students were randomly divided into the traditional lecture-based teaching group (traditional learning [TL] group, 99 students) and TBL teaching group (98 students). The TBL method required the students to prepare the assigned content in advance and discuss some specific topics in small groups. The test scores and questionnaire were applied to evaluate the effects of the two methods. Results: The students in TBL group had higher examination scores (81.70±8.53 vs 74.41±8.27, F[1,195] =124.6, p

We performed a comprehensive real-space simulation study of propagative exciton-polaritons (EPs) of tungsten disulfide (WS2) inside a Fabry–Pérot cavity. Through our simulations, we were able to construct the dispersion relation and determine the propagation length (Lp) of EPs, both of which show sensitive dependence on the applied gate voltage. We found that Lp increases at higher gate voltages when excited at the exciton energy but shows opposite gate dependence at the trion energy. These observations are direct evidence of the coupling between the cavity mode with excitons and trions of WS2. Furthermore, we demonstrate a proof-of-concept device based on the tunable cavity EPs of WS2, which is promising for application as photonic transistors, modulators, or electrical-to-optical converters. Our work unveils the real-space transport properties of gate-tunable cavity EPs and paves the way for future applications of EPs in nanophotonic devices and circuits. [ABSTRACT FROM AUTHOR]

We report a systematic plasmonic study of twisted bilayer graphene (TBLG)-two graphene layers stacked with a twist angle. Through real-space nanoimaging of TBLG single crystals with a wide distribution of twist angles, we find that TBLG supports confined infrared plasmons that are sensitively dependent on the twist angle. At small twist angles, TBLG has a plasmon wavelength comparable to that of single-layer graphene. At larger twist angles, the plasmon wavelength of TBLG increases significantly with apparently lower damping. Further analysis and modeling indicate that the observed twist-angle dependence of TBLG plasmons in the Dirac linear regime is mainly due to the Fermi-velocity renormalization, a direct consequence of interlayer electronic coupling. Our work unveils the tailored plasmonic characteristics of TBLG and deepens our understanding of the intriguing nano-optical physics in novel van der Waals coupled two-dimensional materials.

We report a nanoinfrared (IR) imaging study of the localized plasmon resonance modes of graphene nanoribbons (GNRs) using a scattering-type scanning near-field optical microscope (s-SNOM). By comparing the imaging data of GNRs that are aligned parallel and perpendicular to the in-plane component of the excitation laser field, we observed symmetric and asymmetric plasmonic interference fringes, respectively. Theoretical analysis indicates that the asymmetric fringes are formed due to the interplay between the localized surface plasmon resonance (SPR) mode excited by the GNRs and the propagative surface plasmon polariton (SPP) mode launched by the s-SNOM tip. With rigorous simulations, we reproduce the observed fringe patterns and address quantitatively the role of the s-SNOM tip on both the SPR and SPP modes. Furthermore, we have seen real-space signatures of both the dipole and higher-order SPR modes by varying the ribbon width.

One-dimensional carbon nanomaterials such as carbon nanotubes (CNTs) and graphene nanoribbons (GNRs) are promising for future applications in nanoelectronics and nanophotonics due to their unique characteristics such as topological edge states, chirality, and quantum confinement. Despite the chemical unzipping method of producing GNRs from CNTs, using energetic photons to control light–matter interaction and shape materials at the nanoscale has great promise, especially for chemical-free and on-demand manufacturing. Here, we exploit the high electromagnetic field from a Ti:Sapphire femtosecond laser to interact with CNTs, causing ultrafast energy transfer between the photons and the nanotubes and converting them to GNRs and carbon nanocrystals. Probed with scattering-type scanning near-field optical microscopy, the nanoribbons are identified as semiconducting and/or insulating, a strikingly different electronic phase compared with the original metallic CNTs. Our method of employing high-field and nonequilibrium processes with an ultrafast laser to alter the shape and transform the electronic properties is scalable, does not necessitate high-temperature processes, and is highly spatially controllable—conditions that pave the way for manufacturing nanoscale hybrid materials and devices. [ABSTRACT FROM AUTHOR]

An intelligent tool wear prediction model has been proposed for the micro-grinding tool, optimized using a genetic algorithm (GA) based BP neural network. The GA-BP prediction model is applied with in-situ tool wear detection to obtain training set data and combines cluster analysis to divide the tool wear stages. To represent the uncertainty in wear characteristics, the loss of cross-sectional area of the micro-grinding tool has been selected as an index to evaluate tool wear loss. The K-means clustering algorithm is used to cluster and analyze the tool wear stages under different process parameters. The GA-BP neural network includes five neurons in the input layer: rotating speed, feed rate, cutting depth, grinding length, and the initial cross-sectional area of the tool. The output layer neuron predicts the loss of the tool's cross-sectional area. To validate the method, a series of micro-grinding experiments were performed under different parameters for the micro-groove array of monocrystalline silicon. The loss of the tool's cross-sectional area was measured by a self-made visual inspection system, providing learning samples for the prediction model. The predicted results of the GA-BP neural network model were compared with the traditional Gaussian process regression method. The results show that the GA-BP neural network model can correctly predict tool wear loss and identify wear stages under different process parameters and grinding lengths. It has higher prediction accuracy during the self-learning process, with an average error of 5% .

Psoriasis is a chronic inflammatory disease characterized by increased keratinocyte proliferation and local inflammation. Long noncoding RNAs (lncRNAs) play important regulatory roles in many immune-mediated diseases, including psoriasis. In this study, we aimed to investigate the role and mechanism of lnc-SPRR2G-2 (SPRR2G) in M5-treated psoriatic keratinocytes.Fluorescence in situ hybridization and quantitative real-time polymerase chain reaction (qRT-PCR) showed that lnc-SPRR2G-2 was significantly upregulated in psoriasis tissues and psoriatic keratinocytes. In psoriatic keratinocytes, functional and molecular experiment analyses demonstrated that SPRR2G regulated proliferation, cell cycle and apoptosis, and induced the expression of S100 calcium binding protein A7 (S100A7), interleukin (IL)-1β, IL-8 and C-X-C motif chemokine ligand 10 (CXCL10). The function of SPRR2G in psoriasis is related to the STAT3 signaling pathway and can be inhibited by a STAT3 inhibitor. Moreover, KH-type splicing regulatory protein (KHSRP) was proved to be regulated by lnc-SPRR2G-2 and to control the mRNA decay of psoriasis-related cytokines (p

Cadmium is a kind of heavy metal, which is harmful to environment and human health. Although conventional detection methods based on large instruments such as atomic absorption spectrometers and inductively coupled plasma mass spectrometers have high accuracy, they cannot meet the needs of rapid field detection and high throughput screening. The in situ rapid detection technology of cadmium can provide a new, efficient and real-time method in the fields of food security, agricultural Internet of things, biological breeding and environmental monitoring, especially in the screening of plant varieties with different cadmium absorption and accumulation characteristics. Starting with the principle and characteristics of detection technology, this paper summarized different technologies for rapid in situ detection of cadmium in animals and plants, such as electrochemical sensing technology, fluorescence sensing technology, optical sensor technology, etc., and its research progress, application prospects and development direction in the fields of food safety monitoring, risk assessment, and migration, transformation and accumulation in organisms. It is hoped to provide technical reference for related research and analysis.

We report two cases of tufted angioma with atypical clinical presentations in adults. Patient 1 was a 41-year-old male with painful red plaques on his neck for 2 years. Cutaneous examination showed dark red papules distributed in clusters on the red plaques (7 cm×3.5 cm in size) of the neck, tough texture and some pseudo-vesicular lesions. Laboratory tests revealed a platelet (PLT) count of 83×109/L and abnormal coagulation. Histopathology revealed nodular endothelial cell hyperplasia arranged in tufts and looked like "cannonball" appearance in the dermis and subcutaneous tissue. Immunohistochemical stainings of CD31 and CD34 were positive, and D2-40 was focally positive.Diagnosis: Tufted angioma. The patient refused the treatment with oral propranolol, but was still under follow-up. Patient 2 was a 30-year-old female with a brown nodule on the left dorsal foot, accompanied by pruritus and pain for over two months. Dermatological examination showed a brown nodule in a diameter of about 0.8 cm, with a hard and rough surface. Laboratory tests were normal in routine blood test, liver, kidney and coagulation functions, except elevations in IgG (23.70 g/L) and C3 (0.888 g/L), and ANA 1∶640(+). Histopathological analysis revealed compact arrangement of endothelial cells with tuft proliferation in the dermis. Immunohistochemical stainings of CD31 and CD34 were positive, and D2-40 was focally positive. Diagnosis was tufted angioma. Surgical resection was given.

In order to solve the problem of insufficient thrust measurement accuracy of aeroengine indoor testbed, the thrust calibration experiment technology is studied. Form two aspects of engine static calibration and dynamic calibration, the mechanism of thrust calibration is comprehensively analyzed form the perspective of testbed and engine, and a complete set of operable test specifications is formed. The technical difficulties of engine consistency, inlet temperature deviation and non-standard weather are solved, and the accuracy of thrust transmission process is ensured. The test scheme of indoor test bed calibration is given, and the corresponding ideas and requirements are given according to the test conditions, test bench, calibration engine, test process and result analysis, to ensure the accuracy of calibration results. [ABSTRACT FROM AUTHOR]