Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.329
Filtrar
1.
J Membr Biol ; 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32002589

RESUMO

Endosomal escape is a rate-limiting step in the cytosolic delivery of therapeutic drugs. Overcoming this barrier is crucial to achieve an effective biological based therapy. In this work, we evaluated the ability of a synthetic biomimetic peptide derived from the GALA to facilitate endosomal escape of protein drugs. Our results showed that the cytoplasmic distribution of GALA fusion proteins changed according to the hydrophobicity of GALA. One of the synthetic peptides, GALA3, significantly enhanced the endosomal escape efficiency of protein drugs. The cytosolic delivery capacity of GALA3 was significantly higher than that of several previously reported endosomal escape peptides, including hemagglutinin 2 (HA2). Moreover, when GALA3 was fused to BLF1-HBP, a ribosome-inactivating protein with cell-penetrating peptide HBP, the cytotoxicity of the fusion protein was significantly increased in various cell lines, including H460, HeLa, A549, and SMCC-7721. The growth inhibition effect of GALA3-BLF1-HBP was at least 20 times greater than that of BLF1-HBP alone in different tumor cell lines. GALA3 effectively promoted the endosomal escape of BLF1-HBP in a pH-dependent manner and greatly enhanced the apoptotic activity of BLF1-HBP. Taken together, our data show that by adjusting the hydrophobicity of GALA we obtained a more effective endosomal escape peptide. Therefore, GALA3-fusions can improve the efficiency of therapeutic protein drugs.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32002837

RESUMO

Waste concrete is a key component of construction and demolition (C&D) waste produced in billions of tons. Exploring new technology for recycling waste concrete has become a global concern. Meanwhile, phosphorus (P) removal from wastewater consumes lots of natural minerals, leading to a heavy burden on the environment. In this study, the cement paste powder (HCPP) was used to remove phosphorus from wastewater. The results indicate that both HCPP and thermally modified HCPP (MHCPP) are effective phosphorus removal materials, with a maximum P-binding capacity of 3.9-mg P/g HCPP and 31.2-mg P/g MHCPP, respectively. The phosphorus removal mechanism of HCPP and MHCPP was also proposed: (1) Ca2+ and OH- can release from the surface of the HCPP or MHCPP to wastewater, forming a high-alkaline and Ca-rich solution; (2) hydrolysis of phosphorus species in the high-alkaline solution environment creates HPO42- species; (3) the HPO42- combines with Ca2+ and H2O, resulting in the formation of brushite; (4) the brushite precipitated from wastewater and adhered on the surface of the HCPP or the MHCPP particles. The study provides a new and low-cost material for treatment of phosphorus wastewater. Further, the study also offers a new approach for reusing of waste concrete fines.

4.
Org Lett ; 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32049536

RESUMO

The aggregation-induced emission (AIE) mechanism of restriction of double-bond rotation (RDBR) was utilized to design an excellent solid emitter and sensor for the first time. Thus, cis-tetraphenylethylene (TPE) macrocycle diammoniums were synthesized and bound to a DNA chain by its two ammonium arms. The formed TPE dicycle at the cis position restricted the rotation of the double bond in both the ground and excited states, resulting in AIE enhancement, chiroptical performance enhancement, and sensing enhancement.

5.
6.
Trials ; 21(1): 77, 2020 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-31937335

RESUMO

BACKGROUND: Acupoint selection is a key factor in the treatment of diseases and has not been well studied. The aim of this trial is to explore the differences in efficacy between compatible acupoints and a single acupoint for patients with functional dyspepsia (FD). METHODS: This randomized controlled trial will be conducted in the First Affiliated Hospital of Changchun University of Chinese Medicine in China. Two hundred and sixteen FD patients will be randomly assigned to the compatible acupoints group, single acupoint group, or sham acupuncture group. This trial will include a 1-week baseline period, a 4-week treatment period, and a 4-week follow-up period. During the 4-week treatment period, patients will receive 20 sessions of acupuncture (weekly cycles of one session per day for 5 consecutive days followed by a 2-day break). The primary outcome will be a change in the Nepean Dyspepsia Life Quality Index from baseline to after the 4-week treatment period. Secondary outcome measures will include the dyspeptic symptom sum score, Overall Treatment Effect questionnaire, and 36-item Short Form survey. Adverse events also will be recorded. Ultraweak photon emission and metabolomics tests will be performed at baseline and at the end of treatment to explore the mechanisms of the differences between compatible acupoints and a single acupoint. DISCUSSION: The results of this trial will allow us to compare the difference in efficacy between compatible acupoints and a single acupoint. The findings from this trial will be published in peer-reviewed journals. TRIAL REGISTRATION: Acupuncture-Moxibustion Clinical Trial Registry, AMCTR-IPC-18000176, registered on 4 March 2019; Chinese Clinical Trial Registry, ChiCTR1900023983, registered on 23 June 2019.

7.
Chin J Integr Med ; 26(2): 146-151, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31997237

RESUMO

OBJECTIVE: To evaluate the clinical effectiveness and safety of the Chinese medicine (CM) Qixiong Zhongzi Decoction (, QZD) in the treatment of patients with idiopathic asthenozoospermia. METHODS: A total number of 66 patients with idiopathic asthenozoospermia were included and randomly divided into treatment and control groups by SAS-generated code from January 2015 to August 2016, 33 patients in each group. Patients in the treatment group were administered with 150 mL of QZD twice a day, whereas those in the control group were given 1 g of levocarnitine oral liquid twice a day. The two groups received the indicated medication for 12 weeks and were then followed up for 4 weeks. The primary outcome was sperm motility, and the secondary therapeutic indices were sperm volume, density, pregnancy probability, and CM syndrome score. The comparison between groups was carried out at 4, 8 and 12 weeks, respectively. The safety was determined before and after treatment. RESULTS: (1) Drop-off: 5 cases (7.58%) were lost after treatment (2 from the treatment group and 3 from the control group). (2) Primary outcomes: after 8- and 12-week treatment, the progressive sperms in the two groups were significantly higher than the baseline (all P<0.05); however, the treatment group showed greater improvement compared with the control group at 12-week treatment (22.7% ± 9.0% vs. 14.1% ±8.8%, P<0.05). The increasement of non-progressive grade sperms at both groups was observed at 8- and 12-week treatment with statistical difference (all P<0.05), however, the treatment group showed remarkable improvement compared with the control group at 12-week treatment (38.7% ±14.1% vs. 26.2% ±15.4%, P<0.05). (3) Secondary outcomes: no significant statistical differences were found in semen volume and density (4, 8, and 12-week treatment) and pregnancy probability of patients' wives (12-week treatment) between two groups (all P>0.05), however, the CM syndrome score of the treatment group significantly declined compared with baseline level at each time points (all P<0.05). (4) Safety: no obvious side reactions were found during the treatment in both groups. CONCLUSION: QZD could improve the progressive and non-progressive grade sperm in the treatment of idiopathic asthenozoospermia. It is safe with no obvious side effects.

8.
Mol Pharm ; 17(2): 683-694, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-31913047

RESUMO

Plant-based saponins are amphipathic glycosides composed of a hydrophobic aglycone backbone covalently bound to one or more hydrophilic sugar moieties. Recently, the endosomal escape activity of triterpenoid saponins has been investigated as a potentially powerful tool for improved cytosolic penetration of protein drugs internalized by endocytic uptake, thereby greatly enhancing their pharmacological effects. However, only a few saponins have been studied, and the paucity in understanding the structure-activity relationship of saponins imposes significant limitations on their applications. To address this knowledge gap, 12 triterpenoid saponins with diverse structural side chains were screened for their utility as endosomolytic agents. These compounds were used in combination with a toxin (MAP30-HBP) comprising a type I ribosome-inactivating protein fused to a cell-penetrating peptide. Suitability of saponins as endosomolytic agents was assessed on the basis of cytotoxicity, endosomal escape promotion, and synergistic effects on toxins. Five saponins showed strong endosomal escape activity, enhancing MAP30-HBP cytotoxicity by more than 106 to 109 folds. These saponins also enhanced the apoptotic effect of MAP30-HBP in a pH-dependent manner. Additionally, growth inhibition of MAP30-HBP-treated SMMC-7721 cells was greater than that of similarly treated HeLa cells, suggesting that saponin-mediated endosomolytic effect is likely to be cell-specific. Furthermore, the structural features and hydrophobicity of the sugar side chains were analyzed to draw correlations with endosomal escape activity and derive predictive rules, thus providing new insights into structure-activity relationships of saponins. This study revealed new saponins that can potentially be exploited as efficient cytosolic delivery reagents for improved therapeutic drug effects.

9.
Med Sci Monit ; 26: e918523, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31995551

RESUMO

BACKGROUND Intrathecal dexmedetomidine (DEX) can improve the blockade of spinal anesthesia, but there is no clear conclusion on whether it has an effect on the fetus during cesarean section. Our meta-analysis evaluated the safety and efficacy of intrathecal DEX in cesarean delivery. MATERIAL AND METHODS We searched Cochrane, Embase, PubMed, and CBM for eligible studies, and used the Revised Cochrane Risk of Bias Tool (RoB 2.0) to assess the risk of bias of each study. RevMan was used for statistical analyses. We have registered this meta-analysis on PROSPERO (CRD42019120995). RESULTS The meta-analysis included 10 RCTs, but only 5 were prospectively registered. The results of preregistration studies, including the 1- or 5-min Apgar score (mean difference [MD], -0.03; 95% confidence intervals [CI], -0.16 to 0.10; P=0.64 or MD, 0.00; 95% CI, -0.09 to 0.09; P=1), the umbilical arterial oxygen or carbon dioxide partial pressure (MD, 0.90; 95% CI, -4.92 to 6.72; P=0.76 or MD, 1.20; 95% CI, -2.06 to 4.46; P=0.47), and the cord blood pH (MD, -0.01; 95% CI, -0.05 to 0.03; P=0.72), showed that intrathecal DEX had no significant difference in neonatal outcomes compared with placebo. In maternal outcomes, intrathecal DEX significantly prolonged postoperative pain-free period and reduced the incidence of postoperative shivering, which did not increase spinal anesthesia-associated adverse effects. CONCLUSIONS Intrathecal DEX is safe for the fetus during cesarean section and can improve the blockade effects of spinal anesthesia on puerperae.

10.
Int J Antimicrob Agents ; : 105883, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31923574

RESUMO

The aim of this study was to investigate the susceptibility of respiratory Gram-negative bacteria to ceftolozane/tazobactam and other antibiotics in the Asia-Pacific region during 2015-2016. MICs were determined using the CLSI standard broth microdilution method and interpreted accordingly. Pseudomonas aeruginosa (1574 isolates), Klebsiella pneumoniae (1226), Acinetobacter baumannii (627) and Escherichia coli (476) accounted for 73.1% of 5342 Gram-negative respiratory pathogens. Susceptibility to ceftolozane/tazobactam of individual Enterobacteriaceae was >80%, except for Enterobacter cloacae (76.6%). Ceftolozane/tazobactam inhibited 81.9% of K. pneumoniae and 91.9% of E. coli, with respective MIC50/MIC90 values of 0.5/>32 and 0.25/2 mg/L. For carbapenem-susceptible, ESBL-producing K. pneumoniae and E. coli, susceptibility was 65.5% and 93.3%, respectively, and respective MIC50/MIC90 values were 2/>32 and 0.5/2 mg/L. BlaCTX-M-1 group was most prevalent in selected ESBL-producing K. pneumoniae (40 of 54 isolates) and E. coli (15 of 22 isolates), with ceftolozane/tazobactam susceptibility rates of 50% and 80%, respectively. BlaSHV-ESBL was the second most prevalent, and ceftolozane/tazobactam inhibited 20% of 20 K. pneumoniae isolates with blaSHV-ESBL. The only effective antibiotics for carbapenem-non-susceptible K. pneumoniae (111 isolates) and E. coli (24 isolates) were amikacin and colistin. Ceftolozane/tazobactam was effective against almost all tested P. aeruginosa and carbapenem-non-susceptible strains, with susceptibility of 92.3% and 72.8%, respectively; the respective MIC50/MIC90 values were 1/4 and 2/>32 mg/L. The high susceptibility of ceftolozane/tazobactam remained in different age groups, patient locations, recovery times and countries, except Vietnam. In conclusion, ceftolozane/tazobactam was effective against most respiratory Gram-negative pathogens in the Asia-Pacific region; however, the emergence of carbapenem resistance mandates ongoing surveillance.

11.
Chemosphere ; 242: 125273, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31896195

RESUMO

Atmospheric processing may significantly increase solubility of iron in mineral dust, but the effects of heterogeneous reactions on iron solubility have been poorly understood. In this work, we investigated heterogeneous reaction of NO2 (15 ±â€¯1 and 2.5 ±â€¯0.1 ppmv, equal to ∼3.7 × 1014 and ∼6.2 × 1013 molecule cm-3) with hematite, magnetite and goethite at different relative humidities (RH, 0-90%), and changes in particulate nitrate and soluble iron due to heterogeneous reaction with NO2 were quantified as a function of time (up to 24 h). After reaction with 2.5 ±â€¯0.1 ppmv NO2 for 24 h (or less time), hematite and magnetite were fully saturated, while goethite was only partly deactivated. Nitrate yield was largest for goethite, and the mass ratio of formed nitrate to unreacted mineral only reached ∼1% or less after 24 h reaction. All the three minerals showed low reactivities towards NO2, and the average reactive uptake coefficients of NO2 in the first 3 h were found to be < 5 × 10-8. In addition, the increase in iron solubility was found to be small and in some cases even insignificant for the three minerals after heterogeneous reaction with NO2 for 24 h. Overall, the impacts of heterogeneous reaction of NO2 with hematite, magnetite and goethite on nitrate aerosol formation and iron solubility could be very limited.


Assuntos
Compostos Férricos/química , Óxido Ferroso-Férrico/química , Compostos de Ferro/química , Ferro/química , Minerais/química , Nitratos/análise , Óxidos de Nitrogênio/química , Aerossóis , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/química , Poeira/análise , Modelos Químicos , Solubilidade
12.
J Mater Chem B ; 8(7): 1389-1395, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-31971223

RESUMO

A high-energy self-powered sensing platform for the ultrasensitive detection of proteins is developed based on enzymatic biofuel cells (EBFCs) by using DNA bioconjugate assisted signal amplification. A nitrogen doped ultra-thin carbon shell/gold nanoparticle (N-UHCS/AuNPs) composite was prepared and applied as an electrode supporting substrate to improve the enzyme load. The biocathode of the self-powered sensor is constructed through the step-by-step modification of N-UHCS/AuNPs and bilirubin oxidase (BOD) on carbon paper (CP). To fabricate the bioanode, SiO2 nanospheres@AuNPs-aptamer (SiO2@AuNPs-ssDNA) bioconjugates were prepared and modified on CP. When there is a target protein, the aptamer recognizes it and causes the SiO2@AuNPs-ssDNA bioconjugate to fall off the bioanode, resulting in a significant increase in the open circuit voltage (EOCV) of the sensing device. Under optimal conditions, the developed biosensor shows a wide linear range of 0.1-2000 ng mL-1 with a low detection limit of 21.5 pg mL-1 (S/N = 3). This work shows an effective assay for the sensitive detection of biomolecules by coupling EBFCs, DNA bioconjugates and the biosensing characteristics of smart nanostructures.

14.
Curr Microbiol ; 2020 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-31932997

RESUMO

Fusarium oxysporum f. sp. radicis-lycopersici (Forl) causes Fusarium crown and root rot of tomato, leading to severe yield losses. Chinese chive and the Chinese chive extract reportedly have antifungal effects. In this study, Chinese chive extract treatments inhibited Forl spore germination, with an EC50 of 0.40 g ml-1 in vitro. Furthermore, the mechanism underlying the fungicidal effects of the Chinese chive extract was analyzed by RNA sequencing. A total of 1252 differentially expressed genes (DEGs) were detected, of which 396 were upregulated and 856 were downregulated. The DEGs were related to starch and sucrose metabolism, amino sugar and nucleotide sugar metabolism, galactose metabolism, fatty acid metabolism, sphingolipid metabolism, glycerophospholipid metabolism, peroxisomes, ribosome biogenesis in eukaryotes, mismatch repair, and the phosphatidylinositol signaling system, implying these pathways contribute to the fungicidal activity of the Chinese chive extract. The qRT-PCR results verified the accuracy of the RNA sequencing data. Thus, the Chinese chive extract can inhibit Forl spore germination by affecting spore nutrient metabolism.

15.
IEEE Trans Cybern ; 50(2): 550-560, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30273181

RESUMO

This paper investigates the distributed containment control problem for a class of general second-order multiagent systems with switched dynamics, which is composed of a continuous-time (CT) subsystem and a discrete-time (DT) subsystem. For this switched multiagent system under fixed directed topology, a distributed containment control protocol is proposed for each follower based on the relative local measurements of neighboring followers and leaders. Some necessary and sufficient conditions are derived under the condition that the network topology contains a directed spanning forest, and these conditions ensure that the general second-order containment control problem can be solved under arbitrary CT-DT switching. If the general second-order system is reduced to the double integrator system, some simpler containment conditions are presented. Furthermore, the similar results are also obtained under switching directed topology. Finally, some simulation examples are presented to show the efficiency of the theoretical results.

16.
Sci Total Environ ; 707: 135628, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-31784157

RESUMO

The effect of dams on dissolved inorganic carbon (DIC) transport and riverine ecosystems is unclear in karst cascade reservoirs. Here, we analyzed water samples from a karst river system with seven cascade reservoirs along the Wujiang River, southwestern China, during one hydrological year. From upstream to downstream, the average concentration of DIC increased from 2.2 to 2.6 mmol/L and its carbon isotope composition (δ13CDIC) decreased from -8.0 to -10‰. Meanwhile, the air temperature (Ta) increased from 20.3 °C to 26.7 °C and 10 °C to 13.7 °C in the warm and cold seasons, respectively. The results suggest that a cascade of dams has a stronger effect on DIC dynamics and retention than a single dam. The good correlation between Ta/HRT (hydraulic retention time) and Δ[DIC] as well as Δ[δ13CDIC] mean that Ta and HRT affected the magnitude of the damming effect by altering changes in concentration of DIC and δ13CDIC in the reservoir compared to the inflowing water. In particular, daily regulated reservoirs with short retention times acted more like river corridors and had a smaller effect on carbon dynamics, so modulating retention time might be used reduce the effect of dams on the riverine ecosystem.

17.
AIDS ; 34(2): 189-195, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31634199

RESUMO

OBJECTIVE: CD4CD19 conjugates play an important role in regulating antibody responses and follicular helper T cells development in animal models. However, little is known regarding the characteristic of CD4CD19 conjugates in humans with chronic HIV-1 infection. METHODS: The numbers of CD4CD19 conjugates were counted in 86 HIV-1-infected patients, including 66 typical progressors and 20 complete responders. CD4CD19 conjugates were sorted by flow cytometry and dissociated into CD4 T singlets and CD19 B singlets. The phenotypes of these cells were analyzed in both typical progressors and complete responders, and the levels of HIV-1 DNA in CD4CD19 conjugates were measured in 10 complete responders. RESULTS: We identified CD4CD19 cells as one type of T-B conjugate in peripheral blood, and the numbers and percentages of CD4CD19 conjugates decreased with HIV-1 disease progression. Phenotypic analysis showed CD4CD19 conjugates expressed higher levels of surface CD32. mRNA analysis found that the mRNA levels for CD32b were significantly higher compared with CD32a in CD4CD19 conjugates. Further analysis found that CD4CD19 conjugates expressed higher levels of CCR7 and CXCR5 than CD4 T and CD19 B singlets. A virus infectivity assay showed that CD4CD19 conjugates expressed higher levels of HIV-1-p24 than CD4CD19 cells. CD4CD19 conjugates in lymph node from typical progressors expressed higher levels of HIV-1-p24 than CD4CD19 conjugates in respective peripheral blood. Importantly, CD4CD19 conjugates from complete responders contained higher levels of HIV-1 DNA than total CD4 T cells. CONCLUSION: Our study indicates that CD4CD19 conjugates actively participate in HIV-1 infection and latency, and may serve as a new cellular target to eliminate latency.

18.
Bioorg Chem ; 94: 103346, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31645277

RESUMO

Many natural or synthetic chalcones have potential anti-tumor activity. Here, we synthesized two series of chalcone analogues containing a thieno[2,3-d]pyrimidin-2-yl group and evaluated for their cytotoxic activity towards cultured human lung cancer A549 and colorectal HCT-116 cells. Among them, compound 8d was the most cytotoxic against HCT-116 cells, with an IC50 value of 2.65 µM. Analyses of the phenotypic changes induced by this compound found a dose-dependent accumulation of HCT-116 cells in sub-G1 phase, indicating that compound 8d might induce apoptosis. Furthermore, we found that 8d triggered mitochondrial membrane potential depolarization, promoted reactive oxygen species formation in HCT-116 cells, and increased the percentage of early and late apoptotic cells. Finally, immunoblotting indicated that 8d increased PARP-1 and caspases 3, 7 and 9 cleavage. These data suggest that compound 8d induces apoptosis via the mitochondrial death pathway.

19.
Metab Brain Dis ; 35(1): 83-93, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31440984

RESUMO

Post-stroke fatigue (PSF) is a common symptom after stroke and interferes with the rehabilitation. There are limited pharmacological therapies for managing PSF. Astragalus membranaceus (Huangqi) is a frequently used Chinese herbal medicine (CHM) in the treatment of fatigue in China. The aim of this review was to summarize the efficacy of adjuvant therapy with CHM Huangqi (CHM-HQ) in managing fatigue after stroke. We searched the databases in both English and Chinese for randomized controlled trials (RCTs) on CHM-HQ for PSF till November 2016. The Cochrane risk of bias tool was used to assess the quality of included trials, and the Review Manager 5.3 software was used to conduct the data analysis. Sixteen RCTs with a total of 1222 participants were included. The evidence was poor in quality with unclear or high risks of bias. Compared to routine intervention, treatment with CHM-HQ decreased the fatigue severity based on the assessment of the Fatigue Severity Scale, Fugl-Meyer and Visual Analogue Scale, and improved the quality of life as measured by the Stroke Specific Quality of Life scale, the Barthel index, and the modified Barthel index, while the adverse effects were mild. In conclusions, adjuvant therapy with CHM-HQ may benefit in managing fatigue and quality of life in stroke patients. However, stronger evidence is needed for a promising conclusion and more rigorous designs of RCTs are merited in the future.

20.
J Magn Reson Imaging ; 51(1): 311-318, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31125166

RESUMO

BACKGROUND: Gadolinium-based contrast agents can be used to identify the blood-brain barrier (BBB) opening after inducing a focused ultrasound (FUS) cavitation effect in the presence of microbubbles. However, the use of gadolinium may be limited for frequent routine monitoring of the BBB opening in clinical applications. PURPOSE: To use a gradient-echo sequence without contrast agent administration for monitoring of acoustic cavitation. STUDY TYPE: Animal and phantom prospective. PHANTOM/ANIMAL MODEL: Static and flowing gel phantoms; six normal adult male Sprague-Dawley rats. FIELD STRENGTH/SEQUENCE: 3T, 7T; fast low-angle shot sequence. ASSESSMENT: Burst FUS with acoustic pressures = 1.5, 2.2, 2.8 MPa; pulse repetition frequencies = 1, 10,100 Hz; and duty cycles = 2%, 5%, 10% were transmitted to the chamber of a static phantom with microbubble concentrations = 10%, 1%, 0.1%. MR slice thicknesses = 3, 6, 8 mm were acquired. In flowing phantom experiments, 0.1%, 0.25%, 0.5%, 0.75%, and 1% microbubbles were infused and transmitted by burst FUS with an acoustic pressure = 0.4 and 1 MPa. In in vivo experiments, 0.25% microbubbles was infused and 0.8 MPa burst FUS was transmitted to targeted brain tissue beneath the superior sagittal sinus. The mean signal intensity (SI) was normalized using the mean SI from pre-FUS. STATISTICAL TESTS: Two-tailed Student's t-test. P < 0.05 was considered statistically significant. RESULTS: In the static phantom, the time courses of normalized SI decreases to minimum SI levels of 70-80%. In the flowing phantom, substantial normalized SI of 160-230% was present with variant acoustic pressures and microbubble concentrations. Compared with in vivo control rats, the brain tissue of experimental rats with transmission of FUS pulses exhibited considerable decreases of normalized SI (P < 0.001) because of the cavitation-induced perturbation of flow. DATA CONCLUSION: Observing gradient-echo SI changes can help monitor the targeted location of microbubble-enhanced FUS, which in turn assists the monitoring of the BBB opening. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2020;51:311-318.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA