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Objective: Understansding the changing patterns of in vivo electrical properties for the target tissue is crucial for the accurate temperature monitoring and the treatment efficacy in thermal therapy. Our research aims to investigate the changing patterns and the reversibility of in vivo electrical properties for both healthy livers and liver tumors in a mouse model over a frequency range of 1 Hz to 1 MHz at temperatures between 30 °C to 90 °C.Methods and materials: The mice were anesthetized and the target organ was exposed. An 808-nm near-infrared laser was employed as the heating source to heat the organ in vivo. The four-needle electrode, connected to an impedance analyzer, was utilized to obtain the impedance at varying temperatures, which were monitored by a thermocouple.Results: The findings indicated a gradual decline in impedance with an increase in temperature. Furthermore, the impedance was normalized to that at 30 °C, and the real part of the normalized impedance was defined as the k-values, which range from 0 to 1. The results demonstrated a linear correlation between k-values and temperatures (R2 > 0.9 for livers and R2 > 0.8 for tumors). Significant differences were observed between livers and tumors at 1, 10 and 50 kHz (p < 0.05). Additionally, it was demonstrated that the electrical properties could be reversed when the temperature was below or equal to 45 °C.Conclusion: We believe that these results will contribute to the advancement of radiofrequency ablation systems and the development of techniques for temperature monitoring during liver thermal treatment.
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Hipertermia Induzida , Neoplasias Hepáticas , Fígado , Animais , Camundongos , Neoplasias Hepáticas/terapia , Hipertermia Induzida/métodos , Modelos Animais de Doenças , MasculinoRESUMO
The maize anthracnose stalk rot and leaf blight diseases caused by the fungal pathogen Colletotrichum graminicola is emerging as an important threat to corn production worldwide. In this work, we provide an improved genome assembly of a C. graminicola strain (TZ-3) by using the PacBio Sequel II and Illumina high-throughput sequencing technologies. The genome of TZ-3 consists of 36 contigs with a length of 59.3 Mb. After correction and evaluation with the Illumina sequencing data and BUSCO, this genome showed a high assembly quality and integrity. Gene annotation of this genome predicted 11,911 protein-coding genes, among which 983 secreted protein-coding genes and 332 effector genes were predicted. Compared with previous genomes of C. graminicola strains, TZ-3 genome is superior in nearly all parameters. The genome assembly and annotation will enhance our knowledge of the genetic makeup of the pathogen and molecular mechanisms underlying its pathogenicity and will provide valuable insights into genome variation across different regions. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Colletotrichum , Anotação de Sequência Molecular , Colletotrichum/genética , China , Doenças das Plantas/microbiologiaRESUMO
AIM: To understand the proportion of uHCC (unresectable hepatocellular carcinoma) patients who achieve successful conversion resection in a high-volume setting with state of the art treatment options. METHODS: We retrospectively reviewed all HCC patients hospitalized to our center from June 1st, 2019 to June 1st, 2022. Conversion rate, clinicopathological features, response to systemic and/or loco-regional therapy and surgical outcomes were analyzed. RESULTS: A total of 1,904 HCC patients were identified, with 1672 patients receiving anti-HCC treatment. 328 patients were considered up-front resectable. Of the remaining 1344 uHCC patients, 311 received loco-regional treatment, 224 received systemic treatment, and the remainder (809) received combination systemic plus loco-regional treatment. Following treatment, one patient from the systemic group and 25 patients from the combination group were considered to have resectable disease. A high objective response rate (ORR) was observed in these converted patients (42.3% under RECIST v1.1 and 76.9% under mRECIST criteria). The disease control rate (DCR) reached 100%. 23 patients underwent curative hepatectomy. Major post-operative morbidity was equivalent in the both groups (P=0.76). Pathologic complete response (pCR) was 39.1%. During conversion treatment, grade 3 or higher treatment-related adverse events (TRAEs) were observed in 50% of patients. The median follow-up time was 12.9 months (range, 3.9~40.6) from index diagnosis and 11.4 months (range, 0.9~26.9) from resection. Three patients experienced disease recurrence following conversion surgery. CONCLUSIONS: By intensive treatment, a small sub-group of uHCC patients (2%) may potentially be converted to curative resection. Loco-regional combined with systemic modality was relative safe and effective in the conversion therapy. Short-term outcomes are encouraging, but long-term follow-up in a larger patient population are required to fully understand the utility of this approach.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/cirurgia , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/cirurgia , Neoplasias Hepáticas/patologia , Estudos Retrospectivos , Recidiva Local de Neoplasia/cirurgia , Recidiva Local de Neoplasia/patologia , Terapia CombinadaRESUMO
The hypothalamus and pituitary serve as important neuroendocrine center, which is able to secrete a variety of neuropeptides and hormones to participate in the regulation of reproduction, growth, stress and feeding in fish. Chinese sturgeon is a basal vertebrate lineage fish with a special evolutionary status, but the information on its neuroendocrine system is relatively scarce. Using the transcriptome data on the hypothalamus-pituitary axis of Chinese sturgeon as reference, we found out 46 hypothalamus neuropeptide genes, which were involved in regulation of reproduction, growth, stress and feeding. The results of sequence alignment showed that the neuroendocrine system of Chinese sturgeon evolves slowly, which confirms that Chinese sturgeon is a species with a slow phenotypic evolution rate. In addition, we also isolated six pituitary hormones genes from Chinese sturgeon, including reproductive hormones: follicle-stimulating homone (FSH) and luteinizing hormone (LH), growth-related hormones: growth hormone (GH)/prolactin (PRL)/somatolactin (SL), and stress-related hormone gene: proopiomelanocortin (POMC). Similar to teleost, immunostaining localization analysis in Chinese sturgeon pituitary showed that LH and FSH were located in the pituitary proximal pars distalis, SL was located in the pituitary rostral pars distalis, and POMC was located in the pituitary pars intermedia and pituitary rostral pars distalis. This study will give a contribution to enrich our information on the neuroendocrine system in Chinese sturgeon.
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Neuropeptídeos , Pró-Opiomelanocortina , Animais , Hormônios Hipofisários , Hipófise , Peixes , Hormônio do Crescimento , Prolactina , Neuropeptídeos/genética , Hormônio Luteinizante , Hipotálamo , Hormônio Foliculoestimulante , ChinaRESUMO
Molecularly imprinted polymers (MIPs) are synthetic polymers with specific binding sites that present high affinity and spatial and chemical complementarities to a targeted analyte. They mimic the molecular recognition seen naturally in the antibody/antigen complementarity. Because of their specificity, MIPs can be included in sensors as a recognition element coupled to a transducer part that converts the interaction of MIP/analyte into a quantifiable signal. Such sensors have important applications in the biomedical field in diagnosis and drug discovery, and are a necessary complement of tissue engineering for analyzing the functionalities of the engineered tissues. Therefore, in this review, we provide an overview of MIP sensors that have been used for the detection of skeletal- and cardiac-muscle-related analytes. We organized this review by targeted analytes in alphabetical order. Thus, after an introduction to the fabrication of MIPs, we highlight different types of MIP sensors with an emphasis on recent works and show their great diversity, their fabrication, their linear range for a given analyte, their limit of detection (LOD), specificity, and reproducibility. We conclude the review with future developments and perspectives.
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Impressão Molecular , Polímeros Molecularmente Impressos , Reprodutibilidade dos Testes , Polímeros/química , MúsculosRESUMO
The positive liquid crystals, 4'-heptyl-4-biphenylcarbonitrile (7CB), are used to functionalize carbon nanotubes (LC-CNT), which can be aligned in the liquid crystalline polyimide (LC-PI) matrix under an alternating electric field to fabricate the thermally conductive LC-CNT/LC-PI composite films. The efficient establishment of thermal conduction pathways in thermally conductive LC-CNT/LC-PI composite films with a low amount of LC-CNT is achieved through the oriented alignment of LC-CNT within the LC-PI matrix. When the mass fraction of LC-CNT is 15 wt %, the in-plane thermal conductivity coefficient (λ⥠) and the through-plane thermal conductivity coefficient (λ⥠) of the LC-CNT/LC-PI composite films reach 4.02â W/(m â K) and 0.55â W/(mâ K), which are 90.5 % and 71.9 % higher than those of the intrinsically thermally conductive LC-PI films respectively, also 28.8 % and 5.8 % higher than those of the CNT/LC-PI composite films respectively. Meanwhile, the thermally conductive LC-CNT/LC-PI composite films also possess excellent mechanical and heat resistance properties. The Young's modulus and the heat resistance index are 2.3â GPa and 297.7 °C, respectively, which are higher than the intrinsically thermally conductive LC-PI films and the thermally conductive CNT/LC-PI composite films under the same amount of CNT.
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BACKGROUND: China has a high burden of hepatocellular carcinoma, and hepatitis B virus (HBV) infection is the main causative factor. Patients with hepatocellular carcinoma have a poor prognosis and a substantial unmet clinical need. The phase 2-3 ORIENT-32 study aimed to assess sintilimab (a PD-1 inhibitor) plus IBI305, a bevacizumab biosimilar, versus sorafenib as a first-line treatment for unresectable HBV-associated hepatocellular carcinoma. METHODS: This randomised, open-label, phase 2-3 study was done at 50 clinical sites in China. Patients aged 18 years or older with histologically or cytologically diagnosed or clinically confirmed unresectable or metastatic hepatocellular carcinoma, no previous systemic treatment, and a baseline Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 were eligible for inclusion. In the phase 2 part of the study, patients received intravenous sintilimab (200 mg every 3 weeks) plus intravenous IBI305 (15 mg/kg every 3 weeks). In the phase 3 part, patients were randomly assigned (2:1) to receive either sintilimab plus IBI305 (sintilimab-bevacizumab biosimilar group) or sorafenib (400 mg orally twice daily; sorafenib group), until disease progression or unacceptable toxicity. Randomisation was done using permuted block randomisation, with a block size of six, via an interactive web response system, and stratified by macrovascular invasion or extrahepatic metastasis, baseline α-fetoprotein, and ECOG performance status. The primary endpoint of the phase 2 part of the study was safety, assessed in all patients who received at least one dose of study drug. The co-primary endpoints of the phase 3 part of the study were overall survival and independent radiological review committee (IRRC)-assessed progression-free survival according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 in the intention-to-treat population. The study is registered with ClinicalTrials.gov, NCT03794440. The study is closed to new participants and follow-up is ongoing for long-term outcomes. FINDINGS: Between Feb 11, 2019 and Jan 15, 2020, we enrolled 595 patients: 24 were enrolled directly into the phase 2 safety run-in and 571 were randomly assigned to sintilimab-bevacizumab biosimilar (n=380) or sorafenib (n=191). In the phase 2 part of the trial, 24 patients received at least one dose of the study drug, with an objective response rate of 25·0% (95% CI 9·8-46·7). Based on the preliminary safety and activity data of the phase 2 part, in which grade 3 or worse treatment-related adverse events occurred in seven (29%) of 24 patients, the randomised phase 3 part was started. At data cutoff (Aug 15, 2020), the median follow-up was 10·0 months (IQR 8·5-11·7) in the sintilimab-bevacizumab biosimilar group and 10·0 months (8·4-11·7) in the sorafenib group. Patients in the sintilimab-bevacizumab biosimilar group had a significantly longer IRRC-assessed median progression-free survival (4·6 months [95% CI 4·1-5·7]) than did patients in the sorafenib group (2·8 months [2·7-3·2]; stratified hazard ratio [HR] 0·56, 95% CI 0·46-0·70; p<0·0001). In the first interim analysis of overall survival, sintilimab-bevacizumab biosimilar showed a significantly longer overall survival than did sorafenib (median not reached [95% CI not reached-not reached] vs 10·4 months [8·5-not reached]; HR 0·57, 95% CI 0·43-0·75; p<0·0001). The most common grade 3-4 treatment-emergent adverse events were hypertension (55 [14%] of 380 patients in the sintilimab-bevacizumab biosimilar group vs 11 [6%] of 185 patients in the sorafenib group) and palmar-plantar erythrodysaesthesia syndrome (none vs 22 [12%]). 123 (32%) patients in the sintilimab-bevacizumab biosimilar group and 36 (19%) patients in the sorafenib group had serious adverse events. Treatment-related adverse events that led to death occurred in six (2%) patients in the sintilimab-bevacizumab biosimilar group (one patient with abnormal liver function, one patient with both hepatic failure and gastrointestinal haemorrhage, one patient with interstitial lung disease, one patient with both hepatic faliure and hyperkalemia, one patient with upper gastrointestinal haemorrhage, and one patient with intestinal volvulus) and two (1%) patients in the sorafenib group (one patient with gastrointestinal haemorrhage and one patient with death of unknown cause). INTERPRETATION: Sintilimab plus IBI305 showed a significant overall survival and progression-free survival benefit versus sorafenib in the first-line setting for Chinese patients with unresectable, HBV-associated hepatocellular carcinoma, with an acceptable safety profile. This combination regimen could provide a novel treatment option for such patients. FUNDING: Innovent Biologics. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.
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Anticorpos Monoclonais Humanizados/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Bevacizumab/uso terapêutico , Medicamentos Biossimilares/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Sorafenibe/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Bevacizumab/efeitos adversos , Medicamentos Biossimilares/efeitos adversos , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/virologia , China , Progressão da Doença , Feminino , Hepatite B/virologia , Humanos , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/virologia , Masculino , Pessoa de Meia-Idade , Intervalo Livre de Progressão , Sorafenibe/efeitos adversos , Fatores de Tempo , Adulto JovemRESUMO
The yields of all dissociation channels of ethane dications produced by strong field double ionization were measured. It was found that the branching ratios can be controlled by varying the ellipticity of laser pulses. The CH3+ formation and H+ formation channels show a clear competition, producing the highest and lowest branching ratios at ellipticity of â¼0.6, respectively. With the help of theoretical calculations, such a control was attributed to the ellipticity dependent yields of different sequential ionization pathways.
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In mammals, NK3R is the specific receptor for NKB, which played an important role in reproduction. Recently, two NK3R isoforms, namely NK3Ra and NK3Rb, have been identified in fish. However, little is known about the pituitary actions of the two NK3R isoforms in fish. In this study, both NK3Ra and NK3Rb were isolated from grass carp pituitary. Although their sequence similarity was only 61.6%, the two NK3R isoforms displayed similar ligand selectivity and binding affinity to TAC3 gene products (NKBa, NKBRPa and NKBRPb). In addition, both NK3Ra and NK3Rb displayed similar signaling pathways, including PKA, PKC, MAPK and Ca2+ cascades. Tissue distribution indicated that both NK3Ra and NK3Rb were highly detected in grass carp pituitary. Further study found that NK3Ra was mainly located in pituitary LHß cells, while NK3Rb was only detected in pituitary SLα cells. Furthermore, NK3Ra and NK3Rb activation could induce LHß and SLα promoter activity, respectively. These results suggested that the two NK3R isoforms displayed different pituitary actions in fish. Using grass carp pituitary cells as model, we found that PACAP could significantly reduce NK3Ra, but induce NK3Rb mRNA expression coupled with cAMP/PKA and PLC/PKC pathways. Interestingly, PACAP could also significantly inhibit LHß, but stimulate SLα mRNA expression in grass carp pituitary cells. Furthermore, NK3R antagonist could not only inhibit LHß mRNA expression, but also block PACAP-induced SLα mRNA expression in grass carp pituitary cells. These results suggested that NK3Ra and NK3Rb could mediate PACAP-reduced LHß and -induced SLα mRNA expression in grass carp pituitary, respectively.
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Carpas , Receptores da Neurocinina-3 , Animais , Carpas/metabolismo , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/metabolismo , Hipófise/metabolismo , Hormônios Hipofisários/metabolismo , Receptores da Neurocinina-3/metabolismoRESUMO
Tachykinin 4 (TAC4) is the latest member of the tachykinin family involved in several physiological functions in mammals. However, little information is available about TAC4 in teleost. In the present study, we firstly isolated TAC4 and six neurokinin receptors (NKRs) from grass carp brain and pituitary. Sequence analysis showed that grass carp TAC4 could encode two mature peptides (namely hemokinin 1 (HK1) and hemokinin 2 (HK2)), in which HK2 retained the typical FXGLM motif in C-terminal of tachyinin, while HK1 contained a mutant VFGLM motif. The ligand-receptor selectivity showed that HK2 could activate all 6 NKRs but with the highest activity for the neurokinin receptor 2 (NK2R). Interestingly, HK1 displayed a very weak activation for each NKR isoform. In grass carp pituitary cells, HK2 could induce prolactin (PRL), somatolactin α (SLα), urotensin 1 (UTS1), neuromedin-B 1 (NMB1), cocaine- and amphetamine-regulated transcript 2 (CART2) mRNA expression mediated by NK2R and neurokinin receptor 3 (NK3R) via activation cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA), phospholipase C (PLC)/inositol 1,4,5-triphosphate (IP3)/protein kinase C (PKC) and calcium2+ (Ca2+)/calmodulin (CaM)/calmodulin kinase-II (CaMK II) cascades. However, the corresponding stimulatory effects triggered by HK1 were found to be notably weaker. Furthermore, based on the structural base for HK1, our data suggested that a phenylalanine (F) to valine (V) substitution in the signature motif of HK1 might have contributed to its weak agonistic actions on NKRs and pituitary genes regulation.
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Encéfalo/metabolismo , Proteínas de Peixes/metabolismo , Hipófise/metabolismo , Hormônios Hipofisários/metabolismo , Receptores de Taquicininas/metabolismo , Taquicininas/metabolismo , Animais , Carpas , Proteínas de Peixes/genética , Receptores de Taquicininas/genética , Taquicininas/genéticaRESUMO
Rice blast and bacterial blight are important diseases of rice (Oryza sativa) caused by the fungus Magnaporthe oryzae and the bacterium Xanthomonas oryzae pv. oryzae (Xoo), respectively. Breeding rice varieties for broad-spectrum resistance is considered the most effective and sustainable approach to controlling both diseases. Although dominant resistance genes have been extensively used in rice breeding and production, generating disease-resistant varieties by altering susceptibility (S) genes that facilitate pathogen compatibility remains unexplored. Here, using CRISPR/Cas9 technology, we generated loss-of-function mutants of the S genes Pi21 and Bsr-d1 and showed that they had increased resistance to M. oryzae. We also generated a knockout mutant of the S gene Xa5 that showed increased resistance to Xoo. Remarkably, a triple mutant of all three S genes had significantly enhanced resistance to both M. oryzae and Xoo. Moreover, the triple mutant was comparable to the wild type in regard to key agronomic traits, including plant height, effective panicle number per plant, grain number per panicle, seed setting rate, and thousand-grain weight. These results demonstrate that the simultaneous editing of multiple S genes is a powerful strategy for generating new rice varieties with broad-spectrum resistance.
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Resistência à Doença/genética , Edição de Genes/métodos , Predisposição Genética para Doença , Interações Hospedeiro-Patógeno/genética , Oryza/genética , Ascomicetos , Técnicas de Inativação de Genes , Oryza/microbiologia , XanthomonasRESUMO
Bowman-Birk trypsin inhibitors (BBIs) play important roles in animal and plant immunity, but how these protease inhibitors are involved in the immune system remains unclear. Here, we show that the rice (Oryza sativa) BBI protein APIP4 is a common target of a fungal effector and an NLR receptor for innate immunity. APIP4 exhibited trypsin inhibitor activity in vitro and in vivo. Knockout of APIP4 in rice enhanced susceptibility, and overexpression of APIP4 increased resistance to the fungal pathogen Magnaporthe oryzae. The M. oryzae effector AvrPiz-t interacted with APIP4 and suppressed APIP4 trypsin inhibitor activity. By contrast, the rice NLR protein Piz-t interacted with APIP4, enhancing APIP4 transcript and protein levels, and protease inhibitor activity. Our findings reveal a novel host defence mechanism in which a host protease inhibitor targeted by a fungal pathogen is protected by an NLR receptor.
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Magnaporthe , Oryza , Proteínas NLR , Oryza/genética , Doenças das Plantas , Proteínas de Plantas/genética , Inibidores da TripsinaRESUMO
Potassium (K+) is required by plants for growth and development, and also contributes to immunity against pathogens. However, it has not been established whether pathogens modulate host K+ signaling pathways to enhance virulence and subvert host immunity. Here, we show that the effector protein AvrPiz-t from the rice blast pathogen Magnaporthe oryzae targets a K+ channel to subvert plant immunity. AvrPiz-t interacts with the rice plasma-membrane-localized K+ channel protein OsAKT1 and specifically suppresses the OsAKT1-mediated K+ currents. Genetic and phenotypic analyses show that loss of OsAKT1 leads to decreased K+ content and reduced resistance against M. oryzae. Strikingly, AvrPiz-t interferes with the association of OsAKT1 with its upstream regulator, the cytoplasmic kinase OsCIPK23, which also plays a positive role in K+ absorption and resistance to M. oryzae. Furthermore, we show a direct correlation between blast disease resistance and external K+ status in rice plants. Together, our data present a novel mechanism by which a pathogen suppresses plant host immunity by modulating a host K+ channel.
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Evasão da Resposta Imune , Magnaporthe/fisiologia , Oryza/microbiologia , Canais de Potássio/genética , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Evasão da Resposta Imune/genética , Imunidade Inata/genética , Magnaporthe/patogenicidade , Organismos Geneticamente Modificados , Oryza/genética , Oryza/imunologia , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas , Canais de Potássio/metabolismo , Virulência/genéticaRESUMO
The use of dispersed cross-links with different levels of strength is one of the most successful strategies for toughening a hydrogel. By using a model hydrogel having dispersed association of single-component short alkyl chains, this work demonstrates that the differential modulus-elongation relation derived from tensile curves can reflect the structural evolution of dispersed cross-links at a molecular level. This analysis method allows for decoupling the mechanical contribution of strong and weak hydrophobic clusters, which serve as the minor and major cross-links in our system, respectively. At small deformation, the weak hydrophobic associations majorly determine the stiffness, and their rupture releases folded partial chains to endow deformation capacity. At large deformation, the strength ratio of strong and weak hydrophobic association should be balanced to achieve the optimal strength. Furthermore, the structural parameters of these partial chains, including the Kuhn number, the Kuhn length and the chain conformation, are determined based on scaling theory of extensibility. These results allow for correlating the apparent mechanics to the structural parameters of the dispersed hydrophobic association, paving the way for customized mechanics for specific applications.
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Highly excited electronic states are challenging to explore experimentally and theoretically-due to the large density of states and the fact that small structural changes lead to large changes in electronic character with associated strong nonadiabatic dynamics. They can play a key role in astrophysical and ionospheric chemistry, as well as the detonation chemistry of high-energy density materials. Here, we implement ultrafast vacuum-UV (VUV)-driven electron-ion coincidence imaging spectroscopy to directly probe the reaction pathways of highly excited states of energetic molecules-in this case, methyl azide. Our data, combined with advanced theoretical simulations, show that photoexcitation of methyl azide by a 10-fs UV pulse at 8 eV drives fast structural changes and strong nonadiabatic coupling that leads to relaxation to other excited states on a surprisingly fast timescale of 25 fs. This ultrafast relaxation differs from dynamics occurring on lower excited states, where the timescale required for the wavepacket to reach a region of strong nonadiabatic coupling is typically much longer. Moreover, our theoretical calculations show that ultrafast relaxation of the wavepacket to a lower excited state occurs along one of the conical intersection seams before reaching the minimum energy conical intersection. These findings are important for understanding the unique strongly coupled non-Born-Oppenheimer molecular dynamics of VUV-excited energetic molecules. Although such observations have been predicted for many years, this study represents one of the few where such strongly coupled non-Born-Oppenheimer molecular dynamics of VUV-excited energetic molecules have been conclusively observed directly, making it possible to identify the ultrafast reaction pathways.
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Calcium phosphates (CaP) represent an impressive kind of biomedical material due to their excellent biocompatibility, bioactivity, and biodegradability. Their morphology and structure highly influence their properties and applications. Whilst great progress has been made in research on biomedical materials, there is still a need to develop a method that can rapidly synthesize and screen micro/nanosized biomedical materials. Here, we utilized a microarray screening platform that could provide the high-throughput synthesis of biomedical materials and screen the vital reaction conditions. With this screening platform, 9 × 9 sets of parallel experiments could be conducted simultaneously with one- or two-dimensions of key reaction condition gradients. We used this platform to establish a one-dimensional gradient of the pH and citrate concentration and a two-dimensional gradient of both the Ca/P ratio and pH to synthesize CaP particles with various morphologies. This screening platform also shows the potential to be extended to other reaction systems for rapid high-throughput screening.
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Materiais Biocompatíveis/química , Fosfatos de Cálcio/química , Ensaios de Triagem em Larga Escala/instrumentação , Nanopartículas/química , Dimetilpolisiloxanos/química , Ensaios de Triagem em Larga Escala/métodos , Concentração de Íons de Hidrogênio , Teste de Materiais , Microfluídica , Microscopia Eletrônica de Varredura , Polimetil Metacrilato/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios XRESUMO
For a single, intense 7 µm linearly polarized laser pulse, we found that the branching ratio for the fragmentation of ClCHO+ â Cl + HCO+ , H + ClCO+ , HCl+ +CO depended strongly on the orientation of the molecule (J. Phys. Chem. Lett. 2012, 3 2541). The present study explores the possibility of controlling the branching ratio for fragmentation by using two independent pulses with different frequencies, alignment and delay. Born-Oppenheimer molecular dynamics simulations in the laser field were carried out with the B3LYP/6-311G(d,p) level of theory using combinations of 3.5, 7 and 10.5 µm sine squared pulses with field strengths of 0.03 au (peak intensity of 3.15×1013 W/cm2 ) and lengths of 560 fs. A 3.5 µm pulse aligned with the C-H bond and a 10.5 µm pulse perpendicular to the C-H bond produced a larger branching ratio for HCl+ +CO than a comparable single 7 µm pulse. When the 10.5 µm pulse was delayed by one quarter of the pulse envelope, the branching ratio for the high energy product, (HCl+ +CO 73%) was a factor of three larger than the low energy product (Cl + HCO+ , 25%). By contrast, when the 3.5 µm pulse was delayed by one quarter of the pulse envelope, the branching ratio was reversed (HCl+ +CO 38%; Cl + HCO+ , 60%). Continuous wavelet analysis was used to follow the interaction of the laser with the various vibrational modes as a function of time. © 2018 Wiley Periodicals, Inc.
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Skeletal muscle tissue engineering (SMTE) aims at repairing defective skeletal muscles. Until now, numerous developments are made in SMTE; however, it is still challenging to recapitulate the complexity of muscles with current methods of fabrication. Here, after a brief description of the anatomy of skeletal muscle and a short state-of-the-art on developments made in SMTE with "conventional methods," the use of 3D bioprinting as a new tool for SMTE is in focus. The current bioprinting methods are discussed, and an overview of the bioink formulations and properties used in 3D bioprinting is provided. Finally, different advances made in SMTE by 3D bioprinting are highlighted, and future needs and a short perspective are provided.
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Bioimpressão/métodos , Músculo Esquelético/citologia , Músculo Esquelético/fisiologia , Impressão Tridimensional , Engenharia Tecidual , Alicerces Teciduais , Bioimpressão/instrumentação , Técnicas de Cultura de Células/instrumentação , Técnicas de Cultura de Células/métodos , Células Cultivadas , Humanos , Medicina Regenerativa/instrumentação , Medicina Regenerativa/métodos , Engenharia Tecidual/instrumentação , Engenharia Tecidual/métodos , Alicerces Teciduais/químicaRESUMO
In this study, a tissue-engineered trachea, consisting of multilevel structural electrospun polylactide (PLA) membranes enveloping 3D-printed thermoplastic polyurethane (TPU) skeletons, was developed to create a mechanically robust, antibacterial and bioresorbable graft for the tracheal reconstruction. The study design incorporated two distinct uses of stereocomplex PLA: patterned electrospun fibers to enhance tissue integration compared to the random layered fibers, meanwhile possessing good antibacterial property; and 3D-printed TPU scaffold with elasticity to provide external support and protection. Herein, ionic liquid (IL)-functioned graphene oxide (GO) was synthesized and presented enhanced mechanical and hydrophilicity properties. More interesting, antibacterial activity of the GO- g-IL modified PLA membranes were proved by Escherichia coli and Staphylococcus aureus, showing superior antibacterial effect compared to single GO or IL. The synergistic antibacterial effect could be related to that GO break cytomembrane of bacteria by its extremely sharp edges, while IL works by electrostatic interaction between its cationic structures and electronegative phosphate groups of bacteria membranes, leading to the loss of cell electrolyte and cell death. Hence, after L929 fibroblast cells were seeded on patterned fibrous membranes with phenotypic shape, further effective cell infiltration, cell proliferation and attachment were observed. In addition, the tissue-engineered trachea scaffolds were implanted into rabbit models. The in vivo result confirmed that the scaffolds with patterned membranes manifested favorable biocompatibility and promoted tissue regeneration.
Assuntos
Escherichia coli/crescimento & desenvolvimento , Grafite , Teste de Materiais , Poliésteres , Impressão Tridimensional , Staphylococcus aureus/crescimento & desenvolvimento , Alicerces Teciduais/química , Traqueia/metabolismo , Animais , Linhagem Celular , Elasticidade , Fibroblastos/metabolismo , Grafite/química , Grafite/farmacologia , Camundongos , Poliésteres/química , Poliésteres/farmacologia , Coelhos , Traqueia/patologia , Traqueia/cirurgiaRESUMO
BACKGROUND: Electrical impedance tomography (EIT) is a noninvasive, radiation-free, and low-cost imaging modality for monitoring the conductivity distribution inside a patient. Nowadays, time-difference EIT (tdEIT) is used extensively as it has fast imaging speed and can reflect the dynamic changes of diseases, which make it attractive for a number of medical applications. Moreover, modeling errors are compensated to some extent by subtraction of voltage measurements collected before and after the change. However, tissue conductivity varies with frequency and tdEIT does not efficiently exploit multi-frequency information as it only uses measurements associated with a single frequency. METHODS: This paper proposes a tdEIT algorithm that imposes spectral constraints on the framework of the linear least squares problem. Simulation and phantom experiments are conducted to compare the proposed spectral constraints algorithm (SC) with the damped least squares algorithm (DLS), which is a stable tdEIT algorithm used in clinical practice. The condition number and rank of the matrices needing inverses are analyzed, and image quality is evaluated using four indexes. The possibility of multi-tissue imaging and the influence of spectral errors are also explored. RESULTS: Significant performance improvement is achieved by combining multi-frequency and time-difference information. The simulation results show that, in one-step iteration, both algorithms have the same condition number and rank, but SC effectively reduces image noise by 20.25% compared to DLS. In addition, deformation error and position error are reduced by 8.37% and 7.86%, respectively. In two-step iteration, the rank of SC is greatly increased, which suggests that more information is employed in image reconstruction. Image noise is further reduced by an average of 32.58%, and deformation error and position error are also reduced by 20.20% and 31.36%, respectively. The phantom results also indicate that SC has stronger noise suppression and target identification abilities, and this advantage is more obvious with iteration. The results of multi-tissue imaging show that SC has the unique advantage of automatically extracting a single tissue to image. CONCLUSIONS: SC enables tdEIT to utilize multi-frequency information in cases where the spectral constraints are known and then provides higher quality images for applications.