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2.
Ultrasound Med Biol ; 2021 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-33820668

RESUMO

A combination of ultrahigh-speed optical imaging (5 × 106 frames/s), B-mode ultrasound and passive cavitation detection was used to study the vaporization process and determine both the acoustic droplet vaporization (ADV) and inertial cavitation (IC) thresholds of phospholipid-coated perfluorobutane nanodroplets (PFB NDs, diameter = 237 ± 16 nm). PFB NDs have not previously been studied with ultrahigh-speed imaging and were observed to form individual microbubbles (1-10 µm) within two to three cycles and subsequently larger bubble clusters (10-50 µm). The ADV and IC thresholds did not statistically significantly differ and decreased with increasing pulse length (20-20,000 cycles), pulse repetition frequency (1-100 Hz), concentration (108-1010 NDs/mL), temperature (20°C-45°C) and decreasing frequency (1.5-0.5 MHz). Overall, the results indicate that at frequencies of 0.5, 1.0 and 1.5 MHz, PFB NDs can be vaporized at moderate peak negative pressures (<2.0 MPa), pulse lengths and pulse repetition frequencies. This finding is encouraging for the use of PFB NDs as cavitation agents, as these conditions are comparable to those required to achieve therapeutic effects with microbubbles, unlike those reported for higher-boiling-point NDs. The differences between the optically and acoustically determined ADV thresholds, however, suggest that application-specific thresholds should be defined according to the biological/therapeutic effect of interest.

3.
Nutr Rev ; 2021 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-33822186

RESUMO

CONTEXT: No meta-analyses appeared to have been conducted to examine overall correlations between resonance Raman spectroscopy (RRS)-assessed skin carotenoids and plasma/serum carotenoids. OBJECTIVE: To review the available literature and quantify the association between RRS-assessed skin carotenoids and plasma/serum carotenoids via a meta-analysis of observational studies. DATA SOURCES: To identify relevant publications, we searched the PubMed, Embase, CINAHL, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, ProQuest, and Scopus databases in April 2020 for items combining 3 concepts: Raman spectroscopy, skin, and plasma or serum. DATA EXTRACTION: Criteria for inclusion were publication in a peer-reviewed journal between 1990 and 2020, available in English language, and results reported as a baseline Pearson correlation coefficient. In teams of 2, the researchers independently reviewed titles and abstracts of 2212 nonduplicate papers with initial screening yielding 62 papers for full-text review, of which 15 were deemed eligible for inclusion. DATA ANALYSIS: A random-effects model in R (version 4.0.0) "meta" package was used to analyze the correlation between RRS-assessed skin and plasma/serum carotenoids. A subgroup analysis was conducted for studies involving adults and children, respectively. CONCLUSIONS: The 15 studies included 1155 individuals: 963 adults and 192 children. One study included children and adults. The random-effects model yielded an overall correlation of 0.68 (95%CI, 0.61-0.74; I2 = 74%; P < 0.01). The results were similar when grouped by adults and children. Among 963 adults, the correlation in the random-effects model was 0.69 (95%CI, 0.61-0.75; I2 = 78%; P < 0.01). Among 192 children, the correlation in the random-effects model was 0.66 (95%CI, 0.52- 0.77; I2 = 55%; P = 0.06). Overall, there was a positive, statistically significant correlation between RRS-assessed skin carotenoids and plasma/serum carotenoids in a pooled meta-analysis of 15 studies. SYSTEMATIC REVIEW REGISTRATION: PROSPERO (record number 178835).

4.
Artigo em Inglês | MEDLINE | ID: mdl-33813830

RESUMO

In this paper, we explore the acoustofluidic performance of zinc oxide (ZnO) thin-film surface acoustic wave (SAW) devices fabricated on flexible and bendable thin aluminum (Al) foils/sheets with thicknesses from 50 to 1500 µm. Directional transport of fluids along these flexible/bendable surfaces offers potential applications for the next generation of microfluidic systems, wearable biosensors and soft robotic control. Theoretical calculations indicate that bending under strain levels up to 3000 µÎµ causes a small frequency shift and amplitude change (<0.3%) without degrading the acoustofluidic performance. Through systematic investigation of the effects of the Al sheet thickness on the microfluidic actuation performance for the bent devices, we identify the optimum thickness range to both maintain efficient microfluidic actuation and enable significant deformation of the substrate, providing a guide to design such devices. Finally, we demonstrate efficient liquid transportation across a wide range of substrate geometries including inclined, curved, vertical, inverted, and lateral positioned surfaces using a 200 µm thick Al sheet SAW device.

5.
Plant Physiol Biochem ; 162: 27-35, 2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33662869

RESUMO

Aquaporins (AQPs) involved in water and small molecule transport respond to environmental stress, while it is not clear how arbuscular mycorrhizal fungi (AMF) regulate AQP expression. Here, we investigated the change in leaf water potential and expression level of four tonoplast intrinsic proteins (TIPs), six plasma membrane intrinsic proteins (PIPs), and four nodin-26 like intrinsic proteins (NIPs) genes in trifoliate orange (Poncirus trifoliata) inoculated with Funneliformis mosseae under well-watered (WW), salt stress (SS), and waterlogging stress (WS). Root AMF colonization and soil hyphal length collectively were reduced by SS and WS. Under WW, inoculation with AMF gave diverse responses of AQPs: six AQPs up-regulated, three AQPs down-regulated, and five AQPs did not change. Such up-regulation of more AQPs under mycorrhization and WW partly accelerated water absorption, thereby, maintaining higher leaf water potential. However, under SS, all the fourteen AQPs were dramatically induced by AMF inoculation, which improved water permeability of membranes and stimulated water transport of the host. Under WS, AMF colonization almost did not induce or even down-regulated these AQPs expressions with three exceptions (PtTIP2;2, PtPIP1;1, and PtNIP1;2), thus, no change in leaf water potential. As a result, mycorrhizal plants under flooding may have an escape mechanism to reduce water absorption. It is concluded that AMF had different strategies in response to environmental stresses (e.g. SS and WS) by regulating leaf AQP expression in the host (e.g. trifoliate orange).

6.
ACS Nano ; 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33719408

RESUMO

Red phosphorus (RP) has attracted great attention as a potential candidate for anode materials of high-energy density sodium-ion batteries (NIBs) due to its high theoretical capacity, appropriate working voltage, and natural abundance. However, the low electrical conductance and huge volumetric variation during the sodiation-desodiation process, causing poor rate performance and cyclability, have limited the practical application of RP in NIBs. Herein, we report a rational strategy to resolve these issues by encapsulating nanoscaled RP into conductive and networked carbon nanocages (denoted as RP@CNCs) using a combination of a phosphorus-amine based method and evacuation-filling process. The large interior cavities volume of CNCs and controllable solution-based method enable the ultrahigh RP loading amount (85.3 wt %) in the RP@CNC composite. Benefiting from the synergic effects of the interior cavities and conductive network, which afford high structure stability and rapid electron transport, the RP@CNC composite presents a high systematic capacity of 1363 mA h g-1 at a current density of 100 mA g-1 after 150 cycles, favorable high-rate capability, and splendid long-cycling performance with capacity retention over 80% after 1300 cycles at 5000 mA g-1. This prototypical design promises an efficient solution to maximize RP loading as well as to boost the electrochemical performance of RP-based anodes.

7.
J Colloid Interface Sci ; 593: 41-50, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33744549

RESUMO

The efficient use of abundant renewable bamboo as high value-added decoration and building materials is of great significance for mitigating carbon dioxide emissions and maintaining sustainable development. The key challenge is to explore efficient and gentle methods to improve the undesirable surface properties of bamboo. Herein, a colorful and superhydrophobic bamboo is gently fabricated by a facile in-situ growth and conversion method based on metal-organic framework (for constructing micro-nano composite structures) and subsequent coating of sodium laurate (for reducing surface energy) at room temperature. The resulting sodium laurate-coated cobalt-nickel double hydroxide layer (CoNi-DH-La) is demonstrated as an efficient superhydrophobic layer to exhibit excellent chemical and mechanical stability. Impressively, the as-obtained CoNi-DH-La-coated bamboo sheet (BS-CoNi-DH-La) shows positive performances in terms of mildew resistance, flame retardancy, and self-cleaning. More importantly, this gentle method can endow bamboo with multiple unfading colors by changing the type of inorganic salts during the preparation process and display good potential for large-scale production.

8.
Opt Express ; 29(3): 4159-4173, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33771001

RESUMO

In this paper, we present a method to distinguish neoplastic tissues from non-neoplastic ones using calibration-free laser-induced breakdown spectroscopy (CF-LIBS). For this propose, plasma emission was collected from neoplastic and non-neoplastic tissues taken from the ovarian cancer mice models. Results were obtained by utilizing the characteristic plasma emission lines of different elements that have been confirmed in the investigated samples. From the temporal evolution of plasma emission, the optimum temporal-observation-windows are identified for LIBS investigation. The concentrations of the detected elements in tissues were measured by a calibration-free approach based on data process of plasma parameters at the local thermodynamic equilibrium. The neoplastic specimens provided more energetic plasma than non-neoplastic ones that resulting in higher peaks intensities, electron density and electron temperature especially in the early windows (between 0.1 µs to 0.8 µs). Results demonstrated higher concentrations of major and trace elements such as Mg, Fe, Ca, Na, and K in the neoplastic tissues. Finally, the results using CF-LIBS method were found to be in good agreement with that of Inductive coupled plasma-optical emission spectroscopy (ICP-OES).

9.
Artigo em Inglês | MEDLINE | ID: mdl-33742738

RESUMO

OBJECTIVES: This study aimed to evaluate prognostic value of quantitative flow ratio (QFR) in drug-coated balloon (DCB) angioplasty for in-stent restenosis (ISR). BACKGROUND: There is a high incidence of recurrent ISR after DCB angioplasty. QFR is a novel method for fast computation of fractional flow reserve for the target vessel based on quantitative coronary angiography (QCA) and fluid dynamics algorithms. METHODS: Patients participating in the RESTORE ISR China randomized trial were enrolled and classified into the recurrent restenosis group and the non-recurrent restenosis group. The binary classifications followed the QCA standards of ISR. Clinical and angiographic characteristics of the groups were analyzed, and the QFRs before and after lesion preparation and after final DCB angioplasty were measured and compared. RESULTS: A total of 208 patients who underwent follow-up angiography were enrolled in the study, with 226 lesions measured in total. QFR value after DCB angioplasty (odds ratio [OR] 0.88; 95% confidence interval [CI] 0.83-0.93; p < .0001 for 1 mm increase), lesion length (OR: 1.08; 95% CI: 1.01-1.15; p = .017), and vessel caliber lumen diameter (OR: 0.35; 95% CI 0.13-0.89; p = .027) were independently associated with recurrent restenosis after DCB angioplasty. The optimal QFR cut-off value was determined to be 0.90 with a sensitivity of 0.94, specificity of 0.56, and accuracy of 0.79 in predicting recurrent restenosis. CONCLUSIONS: The QFR value after DCB angioplasty is a promising predictor of DES ISR.

10.
Int J Behav Nutr Phys Act ; 18(1): 44, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33761952

RESUMO

BACKGROUND: The North Carolina (NC) Healthy Food Small Retailer Program (HFSRP) was passed into law with a $250,000 appropriation (2016-2018) providing up to $25,000 in funding to small food stores for equipment to stock healthier foods and beverages. This paper describes an observational natural experiment documenting the impact of the HFSRP on store food environments, customers' purchases and diets. METHODS: Using store observations and intercept surveys from cross-sectional, convenience customer samples (1261 customers in 22 stores, 2017-2020; 499 customers in 7 HFSRP stores, and 762 customers in 15 Comparison stores), we examined differences between HFSRP and comparison stores regarding: (1) change in store-level availability, quality, and price of healthy foods/beverages; (2) change in healthfulness of observed food and beverage purchases ("bag checks"); and, (3) change in self-reported and objectively-measured (Veggie Meter®-assessed skin carotenoids) customer dietary behaviors. Differences (HFSRP vs. comparison stores) in store-level Healthy Food Supply (HFS) and Healthy Eating Index-2010 scores were assessed using repeated measure ANOVA. Intervention effects on diet were assessed using difference-in-difference models including propensity scores. RESULTS: There were improvements in store-level supply of healthier foods/beverages within 1 year of program implementation (0 vs. 1-12 month HFS scores; p = 0.055) among HFSRP stores only. Comparing 2019 to 2017 (baseline), HFSRP stores' HFS increased, but decreased in comparison stores (p = 0.031). Findings indicated a borderline significant effect of the intervention on self-reported fruit and vegetable intake (servings/day), though in the opposite direction expected, such that fruit and vegetable intake increased more among comparison store than HFSRP store customers (p = 0.05). There was no significant change in Veggie Meter®-assessed fruit and vegetable intake by customers shopping at the intervention versus comparison stores. CONCLUSIONS: Despite improvement in healthy food availability, there was a lack of apparent impact on dietary behaviors related to the HFSRP, which could be due to intervention dose or inadequate statistical power due to the serial cross-sectional study design. It may also be that individuals buy most of their food at larger stores; thus, small store interventions may have limited impact on overall eating patterns. Future healthy retail policies should consider how to increase intervention dose to include more product marketing, consumer messaging, and technical assistance for store owners.

11.
Expert Rev Gastroenterol Hepatol ; : 1-13, 2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33691550

RESUMO

Objectives: Serum biomarkers are valuable for clinical decision-making for patients with hepatocellular carcinoma (HCC), among which the most promising are AFP, AFP-L3, DCP, DKK-1, and GP73; however, the efficacy of using combined biomarkers remains controversial. This meta-analysis provides insights regarding this topic.Methods: After systematically surveying the literature available in PubMed, Embase, and Cochrane Library, we identified 28 qualified articles published since January 2015. A random-effects model was used to assess pooled sensitivity, specificity, positive and negative likelihood ratios (PLRs and NLPs), and diagnostic odds ratio (DOR).Results: Values under the summary receiver operating characteristic (SROC) curve varied in different panels of the five biomarkers. Importantly, the sum of sensitivity and specificity of AFP+GP73 was 1.76 (P= 0.0001), which was the best among all the panels. The sum of the triple biomarker panel of AFP, AFP-L3, and DCP was larger (1.64, P= 0.0001) than those of any double biomarker panels of AFP, AFP-L3, and DCP.Conclusions: To the best of our knowledge, this is the first meta-analysis to focus solely on combination assays of multiple biomarkers in HCC. The combined assay of AFP and GP73 conferred the best outcome among all panels. The triple combined panel of AFP, AFP-L3, and DCP showed higher diagnostic potential than individual random double combinations of the three biomarkers. Multiple-biomarker combined assays will be clinically important for decision-making processes for HCC.

12.
Int Orthop ; 2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33768338

RESUMO

PURPOSE: To investigate the indications, approaches, resection methods, and complications of total sacrectomy with a combined antero-posterior approach for malignant sacral tumours. METHODS: Fourteen cases of primary malignant sacral tumours treated with total sacrectomy between January 2012 and 2018 were retrospectively analysed. All patients presented with pre-operative lumbosacral pain or constipation. A combined antero-posterior approach was used for tumour resection, and the spinal pedicle screw rod system was used to achieve ilio-lumbar stability. The visual analogue scale (VAS) and Musculoskeletal Tumor Society (MSTS) scores were used to assess pain and lower limb function, respectively. The mean operative time and intra-operative blood loss were 6.54 hours and 2935 mL, respectively. The mean follow-up period was 62 months. RESULTS: None of the patients died peri-operatively. At the last follow-up, ten patients were continuously disease-free, three were alive with disease, and one died of disease from lung metastasis. Tumour recurrence occurred in three patients. The MSTS scores ranged from 6 to 28 (20.00-93.33%, 6/30-28/30) with an average of 20 (66.67%, 20/30). Seven patients could walk independently in public, five could only walk at home using a walking aid, and two could only lie down and stand for a short time. Thirteen patients developed post-operative complications such as skin necrosis, screw loosening, connecting rod fracture, neuropathic pain, sciatic nerve injury, dysuria, and urinary incontinence. CONCLUSION: Total sacrectomy can effectively treat malignant sacral tumours with good resection boundaries and prognosis. However, the high incidence of post-operative complications may impact post-operative neurological function.

13.
Phys Rev Lett ; 126(8): 085503, 2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-33709763

RESUMO

Under uniaxial shock compression, the steepness of the plastic shock front usually exhibits power law characteristics with the Hugoniot pressure, also known as the "Swegle-Grady law." In this Letter, we show that the Swegle-Grady law can be described better by a third power law rather than the classical fourth power law at the strain rate between 10^{5}-10^{7} s^{-1}. A simple dislocation-based continuum model is developed, which reproduced the third power law and revealed very good agreement with recent experiments of multiple types of metals quantitatively. New insights into this unusual macroscopic phenomenon are presented through quantifying the connection between the macroscopic mechanical response and the collective dynamics of dislocation assembles. It is found that the Swegle-Grady law results from the particular stress dependence of the plasticity behaviors, and that the difference between the third power scaling and the classical fourth power scaling results from different shock dissipative actions.

14.
Artigo em Inglês | MEDLINE | ID: mdl-33676077

RESUMO

Chromatin modification contributes to pluripotency maintenance in embryonic stem cells (ESCs). However, the related mechanisms remain obscure. Here, we show that Npac, a "reader" of histone H3 lysine 36 trimethylation (H3K36me3), is required to maintain mouse ESC (mESC) pluripotency since knockdown of Npac causes mESC differentiation. Depletion of Npac in mouse embryonic fibroblasts (MEFs) inhibits reprogramming efficiency. Furthermore, our Npac ChIP-seq results reveal that Npac co-localizes with histone H3K36me3 in gene bodies of actively transcribed genes in mESCs. Interestingly, we find that Npac interacts with p-TEFb, RNA Pol II Ser2, and Ser5. Depletion of Npac disrupts transcriptional elongation of pluripotency genes Nanog and Rif1. Taken together, we propose that Npac is essential for transcriptional elongation of pluripotency genes by recruiting of p-TEFb and interacting with RNA Pol II Ser2 and Ser5.

15.
Talanta ; 226: 122091, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33676648

RESUMO

Membrane fusion is fundamental to biological activity of cells, so disclosingits relevant mechanism is very important for understanding various cell functions. Although artificial model systems have been developed to uncover the mechanism of membrane fusion, key factors determining the mode of membrane fusion remain unclear. Based on the construction of different types of liposome vesicles, we used a dynamic fluorescence imaging method to investigate the effect of membrane protein distribution density on membrane fusion. Time-resolved imaging revealed that protein-free pure phospholipid vesicles themselves occurred full membrane fusion. Moreover, we prepared proteoliposomes with increasing protein-to-lipid ratio to better reflect the characteristic of membrane structure in vivo. Our data showed that pure phospholipid vesicles no longer fused with the proteoliposomes that in a higher protein proportion, indicating dense membrane proteins may hinder membrane fusion. A further comparative analysis of the interactions of pure phospholipid vesicles with the cell membrane / giant plasma membrane vesicles (GPMVs) / protein-free giant unilamellar vesicles (GUVs) confirmed the inhibitory effect of dense membrane proteins on membrane fusion. Our work demonstrates the membrane protein density influences the mode of membrane fusion and lays a foundation for constructing quasi-native membrane fusion models in vitro.

16.
Artigo em Inglês | MEDLINE | ID: mdl-33787226

RESUMO

Diagnosis and treatment of ovarian cancer are based on intraoperative pathology and debulking surgery. The development of a novel molecular tool is significant for rapid intraoperative pathologic diagnosis, which instructs the decision-making on excision surgery and effective chemotherapy. In this work, we represent a DNA aptamer named mApoc46, which is generated from cell-SELEX by targeting patient-derived primary serous ovarian cancer (pSOC) cells. An average dissociation constant (Kd) was determined to be 0.15 ± 0.05 µM by flow cytometry. The mApoc46 aptamer displays a robust specificity to pSOC cells. Labeled with FAM, mApoc46 can selectively stain living pSOC cells in 30 min without staining commercial OC cell lines and cell lines associated with other cancers. Interestingly, FAM-mApoc46 displayed superb selectivity toward high-grade serous ovarian cancer (HG-SOC) tissues in frozen sections against low-grade SOC, ovarian borderline tumor, other nonepithelial ovarian tumors, and healthy ovarian tissue. These results lead to a potential application in the identification of OCs' histological subtypes during operation. In the patient-derived tumor xenograft NCG mice model, Cy5-labeled mApoc46 was found to accumulate at the tumor area and served as an in vivo imaging probe. The mApoc46 probe shows a robust and stable performance to visualize SOC tumors in the body. Therefore, aptamer mApoc46 holds great potential in rapid intraoperative detection, pathological diagnosis, fluorescence image-guided cancer surgery, and targeted drug delivery and therapy.

17.
Virology ; 558: 110-118, 2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33756423

RESUMO

The Cydia pomonella granulovirus (CpGV) has been used as a biological control agent of codling moth (Cydia pomonella), a severe global pest on pome fruit. Despite the economic importance, our knowledge of its molecular biology is still limited and a detailed picture of its gene expression is still missing. Here, we sequenced the transcriptome of codling moth larvae infected with the Mexican isolate CpGV-M and analyzed the expression of viral genes at 12, 48, and 96 h post infection (hpi). The results showed that two genes (p6.9 and pp31/39K) related to DNA binding of virus production, were highly expressed at 48 and 96 hpi. From 48 to 96 hpi, the expression of genes associated with virus replication and dissemination decreased, whereas the expression of genes related to infectious virion production and per os infectivity increased. This study provides a comprehensive view of CpGV gene expression patterns in host larvae.

19.
Int Ophthalmol ; 2021 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-33783677

RESUMO

PURPOSE: To evaluate the effect of intravitreal injection of ranibizumab (IVR) on subfoveal choroidal thickness (SFCT) and its relationship with central macular thickness (CMT) and best-corrected visual acuity (BCVA) changes in eyes with center-involving DME (CI-DME) using a deep learning-based auto-segmentation. METHODS: This prospective interventional case series included 68 eyes of 68 patients with CI-DME naive to treatment. Morphological optical coherence tomography (OCT) findings of DME were classified into three patterns of structural change: (i) diffuse retinal thickening (DRT), (ii) cystoid macular edema (CME), and (iii) serous retinal detachment (SRD). All patients underwent 3+prorenata IVR. The treated eyes underwent BCVA evaluation and OCT scanning at baseline and months 1, 3, and 6 after the first injection. Then, the choroid layer was measured using a deep learning-based auto-segmentation. RESULTS: At baseline, the mean SFCT and CMT for SRD, DRT, and CME groups were 324.68 ± 65.58 µm and 624.37 ± 77.92 µm, 348.91 ± 45.81 µm and 443.5 ± 78.33 µm, 361.4 ± 64.62 µm, and 536.5 ± 66.02 µm, respectively. After anti-VEGF treatment, the SFCT and CMT have decreased by varying degrees. At 3 and 6 months of treatment, there were no significant changes among these groups. There was no correlation between baseline SFCT and the resulting BCVA (P = 0.670, P = 0.584). There was also no correlation between changes in SFCT and BCVA, CMT (P = 0.344, P = 0.336). CONCLUSION: After treating CI-DME with IVR, SFCT and CMT significantly decreased. However, there were no significant changes among the SRD, DRT, and CME groups. TRIAL REGISTRATION: Trial registration: ChiCTR, ChiCTR-ROC-17013360. Registered 13 November 2017, http://www.chictr.org.cn/ChiCTR-ROC-17013360 .

20.
Ultrason Sonochem ; 73: 105482, 2021 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-33588208

RESUMO

Liquid perfluorocarbon nanodroplets (NDs) are an attractive alternative to microbubbles (MBs) for ultrasound-mediated therapeutic and diagnostic applications. ND size and size distribution have a strong influence on their behaviour in vivo, including extravasation efficiency, circulation time, and response to ultrasound stimulation. Thus, it is desirable to identify ways to tailor the ND size and size distribution during manufacturing. In this study phospholipid-coated NDs, comprising a perfluoro-n-pentane (PFP) core stabilised by a DSPC/PEG40s (1,2-distearoyl-sn-glycero-3-phosphocholine and polyoxyethylene(40)stearate, 9:1 molar ratio) shell, were produced in phosphate-buffered saline (PBS) by sonication. The effect of the following production-related parameters on ND size was investigated: PFP concentration, power and duration of sonication, and incorporation of a lipophilic fluorescent dye. ND stability was also assessed at both 4 °C and 37 °C. When a sonication pulse of 6 s and 15% duty cycle was employed, increasing the volumetric concentration of PFP from 5% to 15% v/v in PBS resulted in an increase in ND diameter from 215.8 ± 16.8 nm to 408.9 ± 171.2 nm. An increase in the intensity of sonication from 48 to 72 W (with 10% PFP v/v in PBS) led to a decrease in ND size from 354.6 ± 127.2 nm to 315.0 ± 100.5 nm. Increasing the sonication time from 20 s to 40 s (using a pulsed sonication with 30% duty cycle) did not result in a significant change in ND size (in the range 278-314 nm); however, when it was increased to 60 s, the average ND diameter reduced to 249.7 ± 9.7 nm, which also presented a significantly lower standard deviation compared to the other experimental conditions investigated (i.e., 9.7 nm vs. > 49.4 nm). The addition of the fluorescent dye DiI at different molar ratios did not affect the ND size distribution. NDs were stable at 4 °C for up to 6 days and at 37 °C for up to 110 min; however, some evidence of ND-to-MB phase transition was observed after 40 min at 37 °C. Finally, phase transition of NDs into MBs was demonstrated using a tissue-mimicking flow phantom under therapeutic ultrasound exposure conditions (ultrasound frequency: 0.5 MHz, acoustic pressure: 2-4 MPa, and pulse repetition frequency: 100 Hz).

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