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1.
Arterioscler Thromb Vasc Biol ; 43(5): 697-712, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36951064

RESUMO

BACKGROUND: The major obstacle for applications of human induced pluripotent stem cells (hiPSCs) is efficient and controlled lineage-specific differentiation. Hence, a deeper understanding of the initial populations of hiPSCs is required to instruct proficient lineage commitment. METHODS: hiPSCs were generated from somatic cells by transduction of 4 human transcription factors (OCT4, SOX2, KLF4, and C-MYC) using Sendai virus vectors. Genome-wide DNA methylation analysis and transcriptional analysis were performed to evaluate the pluripotent capacity and somatic memory state of hiPSCs. Flow cytometric analysis and colony assays were performed to assess the hematopoietic differentiation capacity of hiPSCs. RESULTS: Here, we reveal human umbilical arterial endothelial cell-derived induced pluripotent stem cells (HuA-iPSCs) exhibit indistinguishable pluripotency in comparison with human embryonic stem cells and hiPSCs derived from other tissues of origin (umbilical vein endothelial cells, cord blood, foreskin fibroblasts, and fetal skin fibroblasts). However, HuA-iPSCs retain a transcriptional memory typical of the parental human umbilical cord arterial endothelial cells, together with a strikingly similar DNA methylation signature to umbilical cord blood-derived induced pluripotent stem cells that distinguishes them from other human pluripotent stem cells. Ultimately, HuA-iPSCs are most efficient in targeted differentiation toward hematopoietic lineage among all human pluripotent stem cells based on the functional and quantitative evaluation of both flow cytometric analysis and colony assays. Application of the Rho-kinase activator significantly reduces the effects of preferential hematopoietic differentiation in HuA-iPSCs, reflected in CD34+ cell percentage of day 7, hematopoietic/endothelial-associated gene expression, and even colony-forming unit numbers. CONCLUSIONS: Collectively, our data suggest that somatic cell memory may predispose HuA-iPSCs to differentiate more amenably into hematopoietic fate, bringing us closer to generating hematopoietic cell types in vitro from nonhematopoietic tissue for therapeutic applications.


Assuntos
Células-Tronco Pluripotentes Induzidas , Células-Tronco Pluripotentes , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células Endoteliais/metabolismo , Diferenciação Celular/genética , Cordão Umbilical , Reprogramação Celular
2.
Eur J Pediatr ; 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38954007

RESUMO

To develop a nomogram model for predicting contralateral patent processus vaginalis in children with unilateral inguinal hernia or hydrocele. A retrospective analysis was conducted on 259 children with unilateral inguinal hernia or hydrocele who underwent laparoscopic surgery at the Southern Hospital of Southern Medical University from January 2021 to December 2023. The patients were randomly divided into a training set (n = 207) and a validation set (n = 52) in an 8:2 ratio to analyze the characteristics of CPPV. Multivariate logistic regression analysis was used to screen for independent risk factors for CPPV, and a nomogram prediction model was constructed. The predictive ability, calibration, and clinical net benefit of the model were evaluated by plotting receiver operating characteristic (ROC) curves, calibration curves (HL), and clinical decision curves (DCA). Among children under 1 year old, the laparoscopic exploration revealed a CPPV incidence rate of 55.17%. The incidence rates for children aged 2-10 years ranged from 29.03 to 39.13%, and the incidence rate for children aged 11-14 years was 21.21%. Multivariate logistic regression analysis showed that age (OR = 0.9, 95%CI 0.82-0.99, P = 0.035) and female gender (OR = 2.42, 95%CI 1.21-4.83, P = 0.013) were independent risk factors for CPPV, and the incidence of CPPV decreased with age. The area under the ROC curve (AUC) for the training set of the constructed model was 0.632, and the AUC for the validation set was 0.708. The Hosmer-Lemeshow goodness-of-fit test indicated good model fit (training set P = 0.085, validation set P = 0.221), and the DCA curve suggested good clinical benefit.The nomogram model developed in this study demonstrates good clinical value. Children with unilateral inguinal hernia or hydrocele who are younger in age and female gender should undergo careful intraoperative exploration for the presence of CPPV. What is Known: • The probability of developing inguinal hernia in children with CPPV is 11%-25%, and redo surgery can increase surgical risks and financial burden. • The risk factors of unilateral inguinal hernia combined with CPPV are controversial. What is New: • Age and female gender are independent risk factors for CPPV. • A nomogram prediction model was constructed to provide a theoretical basis as well as an assessment tool for preoperative evaluation of whether children with unilateral indirect inguinal hernia are susceptible to CPPV.

3.
Small ; 19(36): e2301992, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37127857

RESUMO

High-performance microwave absorption (MA) materials have attracted more and more attention because they can effectively prevent microwave radiation and interference from electronic devices. Herein, a new type of MA composite is constructed by introducing carbon nanotubes (CNTs)-anchored metal-organic framework derivatives (MOFDs) into a conductive carbon nanocoil (CNC) network, denoted as CNC/CNT-MOFD. The CNC/MOFD shows a wide effective absorption band of 6.7 GHz under a filling ratio of only 9% in wax-matrix. This is attributed to the hierarchical and porous structures of MOFD bridged by the uniformly dispersed conductive CNC network and the cross-polarization induced by the 3D spiral CNCs. Besides, the as-grown 1D CNTs improve space utilization, porosity, and polarization loss of the composites, resulting in the increase of imaginary permittivity, which further realizes impedance matching and energy attenuation. The Ni nanoparticles in layers of MOFD and at the tips of CNTs generate magnetic loss, promoting the low-frequency absorption ability. Resultantly, RCS values of the optimized composite in all tested theta (θ) ranges are less than -25 dB m2 at 9.5 GHz, effectively reducing the probability of the target detected by the radar.

4.
Small ; : e2308809, 2023 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-38041445

RESUMO

The rational design of absorber size is a promising strategy for obtaining excellent electromagnetic wave (EMW) absorption performance. However, achieving controllable tuning of the material size through simple methods is challenging and the associated EMW attenuation mechanisms are still unclear. In this study, the sizes of metal-organic frameworks (MOFs) are successfully tailored by changing the growth time and the molar ratio of iron (Fe)/organic ligands. The lateral and vertical lengths of MOFs vary in the range of 200 nm to 2 µm and 100 nm to 1 µm, respectively. Both experiments and simulations confirm that the decrease of MOF size favors the formation of more conductive networks, which is beneficial for improving the conductivity loss. Meanwhile, the micromagnetic simulation reveals that the magnetic coupling can be effectively enhanced by the decrease of MOF size, which is conducive to the improvement of magnetic loss, especially in low-frequency range. The reflection loss of Fe-based MOFs with optimized size reaches -46.4 dB at 6.2 GHz with an effective absorption bandwidth of 3.1 GHz. This work illustrates the important role of size effect in EMW dissipation and provides an effective strategy for enhancing the low-frequency EMW absorption performance.

5.
Inorg Chem ; 61(38): 15213-15224, 2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36083838

RESUMO

How to accurately detect and efficiently sweep Cr(VI) from contaminated water has come into focus. Zirconium-based metal-organic frameworks (MOFs) play vital roles in water environmental chemistry due to excellent hydrolysis-resistant stability. However, as photochemical probes and photocatalysts, poor performances in detection sensitivity, selectivity, and photosensitiveness limit sole Zr-MOFs' applications. So, it is urgent to quest valid strategies to break through the dilemmas. Embedding luminous dyes into MOFs has been considered one of the most feasible avenues. Herein, a dual-emissive RhB@Zr-MOF with orange-yellow fluorescence has been assembled by in situ-encapsulating rhodamine B (RhB) into a zirconium-biquinoline-based MOF. Actually, within RhB@Zr-MOF, the aggregation fluorescence quenching (ACQ) effect of RhB molecules was effectively avoided. Notably, RhB@Zr-MOF exhibits a rapid fluorescence quenching response toward Cr(VI) ions with high selectivity, sensitivity, and anti-interference abilities. More interestingly, unlike the most widely reported fluorescence resonance energy transfer (FRET) between MOFs and encapsulated guest modules, photoinduced electron transfer from RhB to Zr-MOF has been confirmed by modeling the ground state and excited states of RhB@Zr-MOF using density functional theory (DFT) and time-dependent DFT (TD-DFT). The effective electron transfer makes RhB@Zr-MOF more sensitive in probing Cr2O72- and CrO42- ions with ultralow detection limit (DL) values of 6.27 and 5.26 ppb, respectively. Prominently, the detection sensitivity based on DL values has been increased about 6 and 9 times, respectively, compared with pristine Zr-MOF. Moreover, rather negative CB and positive VB potentials make RhB@Zr-MOF have excellent photochemical scavenging ability toward Cr(VI) and MO.


Assuntos
Estruturas Metalorgânicas , Zircônio , Cromo , Corantes , Estruturas Metalorgânicas/química , Rodaminas , Água/química , Zircônio/química
6.
Inorg Chem ; 60(11): 8143-8153, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34027670

RESUMO

Chromium Cr(VI) is frequently used in many fields and has been intensively researched for detection and/or removal from contaminated water. However, the existing approaches are still of low efficiency, high cost, and cumbersome in operation. It is thus highly imperative to hunt for alternative avenues to get out of the predicament. In this work, two bcu topological and highly stable zirconium-metal-organic frameworks (Zr-MOFs) of 1 and 2 have been deliberately prepared, displaying channel-type interior spaces replete with free bipyridine/biquinoline matrices and Zr-O defect sites. Because of their unique intrinsic features of high porosity and photosensitivity, 1 and 2 were deployed as versatile platforms to sense, adsorb, and catalytically reduce Cr(VI) ions. Indeed, the Zr-MOF of 1 performs excellently in fluorescence sensing and adsorption trapping of Cr(VI), with an ultralow detection limit of 0.0176 ppm and a fairly high saturated adsorption capacity of 145.77 mg/g, while 2 is more powerful than 1 in photochemical removal of Cr(VI), exhibiting a remarkable reduction efficiency of 98.05% just within 70 min and still up to 92.21% even after five consecutive photocatalytic cycles. Furthermore, possible photoluminescence, quenching, and reduction mechanisms were also tentatively proposed. This study may open up a new avenue for addressing some unresolved environmental issues, that is, the decontamination of highly toxic Cr(VI) from water.

7.
Intern Med J ; 51(12): 2111-2118, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33174303

RESUMO

BACKGROUND: Progress in advance care planning (ACP) in China has been hindered for decades compared with other countries. AIMS: To describe knowledge of ACP, end-of-life (EOL) care preferences and the predictors of patients' preference for ACP, as well as who should mention ACP among Chinese lung cancer patients. METHODS: Questionnaire-based interviews were carried out. Two hundred and fifty-eight lung cancer patients were recruited when first admitted to Tongji Hospital from October 2017 to November 2018. Social-demographic factors, which might influence patients' preference on ACP decisions and who should mention ACP, were evaluated using multivariate logistic regression analysis. RESULTS: A total of 91.1% (n = 235) of patients favoured ACP on EOL issues. One hundred and sixty (60%) patients wanted to make EOL decisions on their own. Only 10% of patients were familiar with advance directions. Eighty-two (31.8%) patients were familiar with do not resuscitate/do not intubate (DNR/DNI) directions. ACP was not mentioned in 92.2% of patients. Gender (male, OR = 4.87 (2.16-5.83)), tumour stage (Stage III, OR = 0.108 (0.06-0.51); Stage IV, OR = 1.780 (1.02-2.11)) and number of children (every increase in the number of children, OR = 0.267 (0.09-0.93)) were the significant predictors of preference for autonomous ACP. Female patients and patients currently receiving treatment are 2.743 and 1.8 times, respectively, more willing to need ACP initiated by doctors. CONCLUSIONS: Chinese patients showed preferences towards ACP, but with inadequate knowledge. More assistance is needed with ACP for those patients, especially for females, patients with one child and those with early stage lung cancer. For female patients and patients receiving treatment, doctors may initiate ACP dialogue first.


Assuntos
Planejamento Antecipado de Cuidados , Neoplasias Pulmonares , Assistência Terminal , Diretivas Antecipadas , Criança , Morte , Feminino , Humanos , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/terapia , Masculino
8.
J Nat Prod ; 83(9): 2567-2577, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32870000

RESUMO

Trillium tschonoskii is a medicinal plant known to biosynthesize steroidal saponins. A phytochemical investigation of the rhizomes of T. tschonoskii led to the isolation of nine new furostanol saponins (1-9) and 11 known analogues (10-20). Five of these new compounds were shown to have hydroxy groups at the C-5 and C-6 positions, while two possess a rare aglycone containing carbonyl groups at the C-16 and C-22 positions as well as a Δ17(20) double bond, and the others have conjugated double bonds in the E-ring or have different sugar chains at the C-3 position. All the isolates were tested for their effect on the expansion of human cord blood (CB) CD34+ hematopoietic stem and progenitor cells. It was found that CB CD34+ cells treated with compounds 6, 7, 9, 10, 14, 15, and 19 showed increased numbers of rigorously phenotype-defined hematopoietic stem cells. Notably, compounds 9, 10, 13, and 14 demonstrated an enhanced ability to increase the percentages and numbers of CB CD34+CD38- cells and multipotential progenitors. The present study is the first to report that furostanol saponins from T. tschonoskii rhizomes can promote hematopoietic stem/progenitor cell (HSPC) expansion.


Assuntos
Sangue Fetal/citologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Saponinas/farmacologia , Trillium/química , Antígenos CD34 , Sequência de Carboidratos , Proliferação de Células , Humanos , Células-Tronco Pluripotentes Induzidas , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Rizoma/química
9.
Int J Mol Sci ; 20(8)2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-31018542

RESUMO

Cord blood (CB) is an attractive source of hematopoietic stem cells (HSCs) for hematopoietic cell transplantation. However, its application remains limited due to the low number of HSCs/progenitors in a single CB unit and its notoriously difficulty in expanding ex vivo. Here, we demonstrated that the human fetal liver sinusoidal endothelial cells engineered to constitutively express the adenoviral E4orf1 gene (hFLSECs-E4orf1) is capable of efficient expansion ex vivo for human CB hematopoietic stem and progenitor cells (HSPCs). Coculture of CD34+ hCB cells with hFLSECs-E4orf1 resulted in generation of substantially more total nucleated cells, CD34+CD38- and CD34+ CD38-CD90+ HSPCs in comparison with that of cytokines alone after 14 days. The multilineage differentiation potential of the expanded hematopoietic cells in coculture condition, as assessed by in vitro colony formation, was also significantly heightened. The CD34+ hCB cells amplified on hFLSECs-E4orf1 were capable of engraftment in vivo. Furthermore, hFLSECs-E4orf1 highly expressed hematopoiesis related growth factor and Notch receptors. Accordingly, the CD34+ hCB cells amplified on hFLSECs-E4orf1 exhibited Notch signaling activation. Taken together, our findings indicated that FLSECs may potentially be the crucial component of the microenvironment to support recapitulation of embryonic HSC amplification in vitro and allow identification of new growth factors responsible for collective regulation of hematopoiesis.


Assuntos
Técnicas de Cocultura/métodos , Células Endoteliais/citologia , Células-Tronco Hematopoéticas/citologia , Fígado/citologia , Animais , Antígenos CD34/análise , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Hematopoese , Transplante de Células-Tronco Hematopoéticas , Humanos , Fígado/embriologia , Camundongos
10.
Macromol Rapid Commun ; 39(6): e1700727, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29356234

RESUMO

Thermoelectric materials can be used as the active materials in thermoelectric generators and as Peltier coolers for direct energy conversion between heat and electricity. Apart from inorganic thermoelectric materials, thermoelectric polymers have been receiving great attention due to their unique advantages including low cost, high mechanical flexibility, light weight, low or no toxicity, and intrinsically low thermal conductivity. The power factor of thermoelectric polymers has been continuously rising, and the highest ZT value is more than 0.25 at room temperature. The power factor can be further improved by forming composites with nanomaterials. This article provides a review of recent developments on thermoelectric polymers and polymer composites. It focuses on the relationship between thermoelectric properties and the materials structure, including chemical structure, microstructure, dopants, and doping levels. Their thermoelectric properties can be further improved to be comparable to inorganic counterparts in the near future.


Assuntos
Polímeros/química , Nanoestruturas/química , Condutividade Térmica
11.
Tumour Biol ; 35(9): 9229-32, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24929328

RESUMO

To investigate the association of LIG1 with the risk of lung cancer, all subjects of unrelated ethnic Han Chinese in Liaoning Province were involved in a hospital-based case-control study. The case group consisted of 370 histologically diagnosed lung cancer patients; 314 controls were selected from cancer-free patients during Dec. 2009 to Dec. 2011. LIG1 rs1050298SNP were analyzed by TaqMan real-time PCR method. All statistical analyses were performed with Statistical Product and Service Solution sv13.0 (SPSS). The genotype distribution frequency of LIG1 rs1050298 SNP displayed significant difference between the case and the control group. Individuals carrying the LIG1 rs1050298 T genotype had higher risks of lung cancer, especially those with squamous cell carcinoma.


Assuntos
DNA Ligases/genética , Predisposição Genética para Doença/genética , Neoplasias Pulmonares/genética , Polimorfismo de Nucleotídeo Único , Adenocarcinoma/etnologia , Adenocarcinoma/genética , Povo Asiático/genética , Carcinoma de Células Escamosas/etnologia , Carcinoma de Células Escamosas/genética , Estudos de Casos e Controles , China , DNA Ligase Dependente de ATP , Feminino , Frequência do Gene , Predisposição Genética para Doença/etnologia , Genótipo , Humanos , Neoplasias Pulmonares/etnologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Reação em Cadeia da Polimerase , Fatores de Risco
12.
Adv Mater ; 36(24): e2314346, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38582970

RESUMO

Electrowetting-on-dielectric (EWOD), recognized as the most successful electrical droplet actuation method, is essential in diverse applications, ranging from thermal management to microfluidics and water harvesting. Despite significant advances, it remains challenging to achieve repeatability, high speed, and simple circuitry in EWOD-based droplet manipulation on superhydrophobic surfaces. Moreover, its efficient operation typically requires electrode arrays and sophisticated circuit control. Here, a newly observed droplet manipulation phenomenon on superhydrophobic surfaces with orbital EWOD (OEW) is reported. Due to the asymmetric electrowetting force generated on the orbit, flexible and versatile droplet manipulation is facilitated with OEW. It is demonstrated that OEW droplet manipulation on superhydrophobic surfaces exhibits higher speed (up to 5 times faster), enhanced functionality (antigravity), and manipulation of diverse liquids (acid, base, salt, organic, e.g., methyl blue, artificial blood) without contamination, and good durability after 1000 tests. It is envisioned that this robust droplet manipulation strategy using OEW will provide a valuable platform for various processes involving droplets, spanning from microfluidic devices to controllable chemical reactions. The previously unreported droplet manipulation phenomenon and control strategy shown here can potentially upgrade EWOD-based microfluidics, antifogging, anti-icing, dust removal, and beyond.

13.
Cell Prolif ; 56(11): e13486, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37096780

RESUMO

Blood supply shortages, especially the shortage of rare blood types, threaten the current medical system. Research on stem cells has shed light on in vitro blood cell manufacturing. The in vitro production of universal red blood cells (RBCs) from induced pluripotent stem cells (iPSCs) has become the focus of transfusion medicine. To obtain O-type Rh D-negative blood, we developed O-type Rh D-negative human (h)iPSCs using homology-directed repair (HDR)-based CRISPR/Cas9. HuAiPSCs derived from human umbilical arterial endothelial cells and showing haematopoietic differentiation preferences were selected for gene modification. Guide RNAs (gRNAs) were selected, and a donor template flanked by gRNA-directed homologous arms was set to introduce a premature stop code to RHD exon 2. CRISPR/Cas9 gene editing has resulted in the successful generation of an RHD knockout cell line. The HuAiPSC-A1-RHD-/- cell line was differentiated into haematopoietic stem/progenitor cells and subsequently into erythrocytes in the oxygen concentration-optimized differentiation scheme. HuAiPSC-A1-RHD-/- derived erythrocytes remained positive for the RBC markers CD71 and CD235a. These erythrocytes did not express D antigen and did not agglutinate in the presence of anti-Rh D reagents. In conclusion, taking the priority of haematopoietic preference hiPSCs, the HDR-based CRISPR/Cas9 system and optimizing the erythroid-lineage differentiation protocol, we first generated O-type Rh D-negative universal erythrocytes from RHD knockout HuAiPSCs. Its production is highly efficient and shows great potential for clinical applications.


Assuntos
Sistemas CRISPR-Cas , Células-Tronco Pluripotentes Induzidas , Humanos , Sistemas CRISPR-Cas/genética , Células Endoteliais , Eritrócitos/metabolismo , Edição de Genes/métodos , Linhagem Celular , Células-Tronco Pluripotentes Induzidas/metabolismo
14.
Nano Lett ; 11(6): 2202-5, 2011 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-21563786

RESUMO

Interlayering 17.5 nm of Yttria-doped ceria (YDC) thin films between bulk yttria-stabilized-zirconia electrolyte and a porous Pt cathode enhanced the performance of low-temperature solid oxide fuel cells. The added YDC interlayer (14.11% doped Y(2)O(3)) was fabricated by atomic layer deposition and reduced the cathode/electrolyte interfacial resistances while increasing the exchange current density j(0) by a factor of 4 at operating temperatures between 300-500 °C. Tafel plots and the fitted impedance data suggest that the charge transfer coefficient α of interlayered SOFCs was 1.25 times higher, and the electrode/interfacial activation energy was reduced from 0.85 to 0.76 eV.


Assuntos
Cério/química , Membranas Artificiais , Óxidos/química , Ítrio/química , Íons/química , Cinética , Tamanho da Partícula , Propriedades de Superfície
15.
Ying Yong Sheng Tai Xue Bao ; 33(11): 2997-3006, 2022 Oct.
Artigo em Zh | MEDLINE | ID: mdl-36384834

RESUMO

Livestock wastewater is an important reservoir of antibiotic resistance genes (ARGs), with high environmental risks. We investigated the seasonal variations of distribution and removal of swine wastewater originated high-risk tetracycline resistance genes (TRGs) in horizontal subsurface flow constructed wetlands. The effects of exogenous addition of tetracycline (TC) and copper ion (Cu2+) on the abundance of TRGs in effluent with single and combined pollution of antibiotic and heavy metal were studied. The results showed that all the three high-risk TRGs (tetM, tetO and tetW) were detected in swine wastewater. Wetlands could effectively reduce the ARGs, with the absolute abundance of TRGs in effluent being decreased by 1.1-2.4 and 1.7-2.9 orders of magnitude in summer and winter compared with the influent, respectively. The abundance of TRGs in wetland soils showed the characte-ristics that the outflow side was lower than the inflow side, the non-rhizosphere area was lower than the rhizosphere area, and lower in winter than in summer. In summer and winter, single and combined pollution of TC and Cu2+ in swine wastewater would increase the abundance of TRGs in effluent compared with that in the control. The constructed wetland is suitable for controlling the environmental diffusion of ARGs in livestock wastewater.


Assuntos
Resistência a Tetraciclina , Áreas Alagadas , Suínos , Animais , Resistência a Tetraciclina/genética , Águas Residuárias , Estações do Ano , Genes Bacterianos , Tetraciclina , Antibacterianos
16.
Angle Orthod ; 2022 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-35849081

RESUMO

OBJECTIVES: To analyze the mandibular retromolar space among normal-divergent adult patients with different sagittal skeletal patterns by cone-beam computed tomography (CBCT). MATERIALS AND METHODS: CBCTs of a total of 120 normal-divergent adult patients were investigated. Patients were categorized into the following three groups according to their ANB angle: skeletal Class I (48 patients), skeletal Class II (36 patients), and skeletal Class III (36 patients). Four different planes parallel to the mandibular occlusal plane were used to measure the retromolar space. The retromolar space was measured by two reference lines and then compared between different sagittal skeletal patterns groups. The incidence of root contact with the inner lingual cortex was compared among the three groups. RESULTS: The retromolar space of the Class III patients was significantly larger than that of Class I patients and Class II patients. Compared with Class I and Class III patients, Class II patients had a smaller retromolar space and higher incidence of contact with the inner cortex of the mandible. CONCLUSIONS: Class III patients had a larger retromolar space than Class I patients and Class II patients in four different planes. The mandibular retromolar space should be evaluated by CBCT in patients who need mandibular molar distalization.

17.
Nanomaterials (Basel) ; 12(15)2022 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-35957060

RESUMO

A flexible and stretchable electrode based on polydimethylsiloxane (PDMS)-Ag nanosheet composite with low resistance and stable properties has been investigated. Under the synergistic effect of the excellent flexibility and stretchability of PDMS and the excellent electrical conductivity of Ag nanosheets, the electrode possesses a resistivity as low as 4.28 Ωm, a low resistance variation in the 0-50% strain range, a stable electrical conductivity over 1000 cycles, and a rapid recovery ability after failure caused by destructive large stretching. Moreover, the conductive mechanism of the flexible electrode during stretching is explained by combining experimental tests, theoretical models of contact point-tunneling effect, and finite element simulation. This research provides a simple and effective solution for the structure design and material selection of flexible electrodes, and an analytical method for the conductive mechanism of stretchable electrodes, which has potential for applications in flexible electronic devices, smart sensing, wearable devices, and other fields.

18.
Anal Chim Acta ; 1224: 340201, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35998986

RESUMO

The sensitivity of surface enhanced Raman spectroscopy (SERS) depends on the construction of "hot spots" and the number of analyte molecules adsorbed onto the substrates. Herein, we have constructed a kind of SERS substrate based on gold nanostars (Au NSs) coated with nickel-cobalt layered double hydroxide (LDH) using a zeolitic imidazolate skeleton as sacrificial template via nickel ions etching. LDH was used as the absorption medium for target molecules, and concurrently prevented Au NSs from agglomeration to improve stability and uniformity of the substrate. Meanwhile, encapsulated Au NSs were used as the enhancement medium for Raman detection. The porous LDH shell around the Au NSs promoted the target molecules to approach the Au NSs, which was certified by the experimental results of UV-Vis absorption and simulation analysis using the density functional theory. The detection of Rhodamine 6G solution with a concentration of 10-9 M was realized by the AuNS/LDH, and the relative standard deviation of Raman signals was less than 10%. Therefore, this work provides a new idea and a suitable structure to improve SERS signal intensity by introducing adsorption medium into the SERS substrate.


Assuntos
Nanopartículas Metálicas , Análise Espectral Raman , Adsorção , Ouro/química , Nanopartículas Metálicas/química , Níquel , Análise Espectral Raman/métodos
19.
Nanoscale ; 14(18): 7025-7038, 2022 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-35471502

RESUMO

A flexible humidity sensor based on a tissue-carbon nanocoil (CNC)-carbon nanotube (CNT) composite has been investigated. Taking advantage of the excellent water absorption of tissue and the electrical sensitivity of CNCs/CNTs to humidity, this humidity sensor obtains outstanding humidity sensing performance, including a wide sensing range of 10-90% RH, a maximum response value of 492% (ΔR/R0) at 90% RH, a maximum sensitivity of 6.16%/% RH, a good long-time stability of more than 7 days, a high humidity resolution accuracy of less than 1% RH and a fast response time of 275 ms. Furthermore, the sensor also exhibits robust bending (with a curvature of 0.322 cm-1) and folding (up to 500 times) durability, and after being made into a complex "thousand paper crane" shape it still provides stable humidity sensing performance. As a proof of concept, this humidity sensor demonstrates excellent responsivity to human breath monitoring, non-contact fingertip humidity detection, water boiling detection and air humidity monitoring, indicating great potential in the fields of wearable devices, weather forecasting systems and other intelligent humidity monitoring devices.

20.
J Colloid Interface Sci ; 624: 320-337, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-35660901

RESUMO

Bimetallic nanostructures composited with carbonaceous materials are the potential contenders for quantitative glucose measurement owing to their unique nanostructures, high biomimetic activity, synergistic effects, good conductivity and chemical stability. In the present work, chemical vapors deposition technique has been employed to grow 3D carbon nanocoils (CNCs) with a chiral morphology on hierarchical macroporous nickel foam (NF) to get a CNCs/NF scaffold. Following, bimetallic Cu@Ni core-shell nanoparticles (CSNPs) are effectively coupled with this scaffold through a facile solvothermal route in order to fabricate a binder-free novel Cu@Ni CSNPs/CNCs/NF hybrid nanostructure. The constructed free-standing 3D hierarchical composite electrode guarantees highly efficient glucose redox activity due to core-shell synergistic effects, enhanced electrochemical active surface area, excellent electrochemical stability, improved conductivity with better ion diffusivity and accelerated reaction kinetics. Being a non-enzymatic glucose sensor, this electrode achieves highly swift response time of 0.1 s, ultra-high sensitivity of 6905 µA mM-1 cm-2, low limit of detection of 0.03 µM along with potential selectivity and good storage stability. Moreover, the proposed sensor is also tested successfully for the determination of glucose concentration in human serum samples under good recovery ranging from 96.6 to 102.1 %. The 3D Cu@Ni CSNPs/CNCs/NF composite electrode with unprecedented catalytic performance can be utilized as an ideal biomimetic catalyst in the field of non-enzymatic glucose sensing.


Assuntos
Nanopartículas , Níquel , Carbono , Técnicas Eletroquímicas/métodos , Eletrodos , Glucose , Humanos , Níquel/química
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