Safety findings after intravenous administration of sulfur hexafluoride microbubbles to 463,434 examinations at 24 centers.

OBJECTIVES: We aimed to evaluate the safety of the ultrasound contrast agent sulfur hexafluoride microbubbles in a large group of patients referred for routine contrast-enhanced ultrasound (CEUS). METHODS: A retrospective assessment was made of all patients that received sulfur hexafluoride microbubbles intravenously for CEUS at 24 centers between January 2006 and April 2019. Patient demographic details, examination type, and the dose of sulfur hexafluoride microbubbles administered were recorded with specific adverse events (AEs) documentation tools at each center. All AEs were recorded as serious or non-serious. Non-serious AEs were classified by intensity as mild, moderate, or severe according to ACR criteria. The frequencies of AEs across patient subgroups were compared using the chi-square test. RESULTS: A total of 463,434 examinations were evaluated. Overall, 157 AEs (153 [0.033%] non-serious; 4 [0.001%] serious) were reported after sulfur hexafluoride microbubbles administration, giving an AE frequency of 0.034% (157/463,434). Among the non-serious AEs, 66 (0.014%) were mild, 70 (0.015%) moderate, and 17 (0.004%) severe in intensity. The liver was the most common examination site, presenting an AE frequency of 0.026%. The highest AE frequency (0.092%) was for patients undergoing CEUS for vascular disease. There were no significant gender differences in either the total number or the severity of non-serious AEs (chi-square = 2.497, p = 0.287). The onset of AEs occurred within 30 min of sulfur hexafluoride microbubbles administration in 91% of cases. CONCLUSION: The frequency of AEs to sulfur hexafluoride microbubbles is very low and severe reactions are rare, confirming that sulfur hexafluoride microbubbles are appropriate for routine CEUS applications. KEY POINT: • The frequency of AEs to sulfur hexafluoride microbubbles is very low and severe reactions are rare.

Analysis of factors associated with the umbilical cord pitch value by ultrasound measurement in late pregnancy.

BACKGROUND: This study aimed to investigate the factors associated with the antenatal umbilical cord pitch value by ultrasound measurement in late pregnancy. We investigated the factors associated with the umbilical cord pitch value under prenatal ultrasound measurement. METHODS: This study included 528 pregnant women who underwent routine antenatal ultrasound examinations in Ningbo Women and Children's Hospital from December 2020 to August 2021. Their umbilical cord pitch values and diameter, Wharton's jelly thickness, amniotic fluid indexes, umbilical artery blood flow parameters, and other relevant data, such as ages and gestational ages, were measured. Information about delivery methods, placenta, umbilical cord, and neonatal weight were recorded during follow-up. Statistical analysis was performed on the above data, and the factors associated with the pitch values were analyzed by linear regression. RESULTS: This study revealed that cord torsion (p < 0.001, 95% confidence interval [CI]=-34.81 to -19.01), cord entanglement (p < 0.001, 95% CI = 10.71 to 20.11), thickening of Wharton's jelly (p = 0.001, 95% CI = 5.39 to 20.24), and cord edema (p = 0.015, 95%CI = 2.09 to 19.44), gestational age (p = 0.024, 95%CI = 0.14 to 1.89), age of pregnant woman (p = 0.009, 95%CI= -1.15 to -0.16), and neonatal weight (p = 0.011, 95%CI = 0.002 to 0.012) were significantly correlated with the pitch values. CONCLUSION: The umbilical cord pitch value significantly correlated with cord entanglement, cord torsion, cord edema, Wharton's jelly thickening, gestational age, age of the pregnant woman, and neonatal weight. Notably, the pitch value by prenatal ultrasound measurement is predictive of cord morphological abnormalities such as cord entanglement, cord torsion, cord edema, and Wharton's jelly thickening.

TiSe2-mediated sonodynamic and checkpoint blockade combined immunotherapy in hypoxic pancreatic cancer.

BACKGROUND: Pancreatic cancer remains among the most prevalent and aggressive forms of cancer. While immunotherapeutic treatment strategies have shown some promise in affected patients, the benefits of these interventions have been limited by insufficient tumor infiltration by activated T cells. RESULTS: Here, Titanium diselenide (TiSe2) nanosheets were synthesized with good stability. When exposed to ultrasound (US), the TiSe2 nanosheets served as a reliable nano-sensitizer capable of inducing large amounts of reactive oxygen species (ROS) mediating sonodynamic therapy (SDT) under hypoxic and normoxic conditions. The tumor-released TAAs induced by TiSe2 nanosheet-mediated SDT promoted immunogenic cell death (ICD) conducive to the maturation of dendritic cells (DCs), and cytokine secretion and the subsequent activation and infiltration of T cells into the tumor. Combining TiSe2-mediated SDT with anti-PD-1 immune checkpoint blockade treatment led to the efficient suppression of the growth of both primary tumor and distant tumor, while simultaneously preventing lung metastasis. These improved immunotherapeutic and anti-metastatic outcomes were associated with activated systematic antitumor immune responses, including the higher levels of DC maturation and cytokine secretion, the increased levels of CD8+ T cells and the decreased levels of Treg cells infiltrated in tumors. CONCLUSION: TiSe2 can be used as a sonosensitizer with good efficacy and high safety to mediate efficient SDT. The combination treatment strategy comprised of TiSe2-mediated SDT and PD-1 blockade activate anti-tumor immune responses effectively thorough inducing ICD, resulting in the inhibition the growth and metastasis of tumor. The combination therapy holds promise as a novel immunotherapy-based intervention strategy for pancreatic cancer patients.

Cavitation assisted endoplasmic reticulum targeted sonodynamic droplets to enhanced anti-PD-L1 immunotherapy in pancreatic cancer.

BACKGROUND: Sonodynamic therapy (SDT) induces immunogenic cell death (ICD) in tumors and promises to play an assistive role in immunotherapy in pancreatic cancer. However, the short half-life and limited diffusion distance of reactive oxygen species (ROS) impair ICD induction, especially in tumors with relatively poor blood perfusion and dense stroma. RESULTS: To address this problem, we fabricated cavitation-assisted endoplasmic reticulum (ER) targeted sonodynamic nanodroplets (PMPS NDs, 329 nm). The good sonodynamic effect and precise endoplasmic reticulum target effect was verified. After intravenous injection, the cRGD peptide modified nanodroplets initially aggregated around the tumor vascular endothelial cells. Stimulated by ultrasound, the liquid-to-gas bubbles began to oscillate and cavitate. This acoustic droplet evaporation strategy facilitated transport of the nanoparticle across the vessel, with deep penetration. This loosened the tumor stroma and facilitated accumulation and penetration of loaded sonosensitizer after 6 h. The modified sonosensitizer can selectively accumulate in the ER to generate a large amount of ROS in situ, inducing potent ER stress, amplified ICD and dendritic cell maturation in vitro and in vivo. Furthermore, the elevated antitumor effect of SDT plus anti-PD-L1 immunotherapy was verified using an orthotopic tumor model. CONCLUSIONS: This study reports a cavitation assisted ER targeted sonodynamic therapy that can enhance the effect of anti-PD-L1 immunotherapy effectively in orthotopic and distant pancreatic cancer.

Deep Penetration of Targeted Nanobubbles Enhanced Cavitation Effect on Thrombolytic Capacity.

Sonothrombolysis with microbubbles can enhance the dissolution of thrombus through the cavitation effect of microbubbles under ultrasound irradiation. However, the detailed mechanism of thrombolysis with microscaled or nanoscaled bubbles is still not so clear. This study compared the thrombolytic capacity of cRGD-targeted or nontargeted bubbles with different particle sizes combined with urokinase (UK). The size of the microscaled bubbles (Mbs or Mbs-cRGD) was mostly approximately 3 µm, while the nanoscaled bubbles (Nbs or Nbs-cRGD) were mainly around 220 nm. In vitro testing was performed on an extracorporeal circulation device that mimics human vascular thromboembolism. The rabbit clots in Mbs with UK groups showed peripheral worm-like dissolution, while the clots in Nbs with UK groups showed internal fissure-like collapse. In addition, the thrombolysis rate of Nbs-cRGD with the UK group was the highest. Furthermore, the scanning electron microscopic images showed that the fibrin network was the most severely damaged by the Nbs-cRGD, and most of the fibrin strands were dissolved. Especially, the Nbs-cRGD can penetrate much deeper than Mbs-cRGD into the thrombus and loosen the fibrin network. Taken together, benefiting from the specific identification and deep penetration to thrombus, our developed novel targeted Nbs may have broad application prospects in the clinic.

Effects of high-intensity focused ultrasound on cisplatin-resistant human lung adenocarcinoma in vitro and in vivo.

It is widely accepted that high-intensity focused ultrasound (HIFU) is a minimally invasive treatment option for different tumors, but its roles and the corresponding mechanism in cisplatin (DDP) chemoresistance in lung adenocarcinoma (LA) remain unclear. In this study, we investigated the response of DDP-resistant LA cells to HIFU and its underlying molecular mechanisms using molecular biology techniques. It was found that HIFU exposure inhibited the proliferation of DDP-resistant A549 (A549/DDP) cells through arresting cell cycle at the G1/G0 phase via the Cyclin-dependent pathway and promoting apoptosis in a Bcl-2-dependent manner. Furthermore, the results also showed that HIFU exposure could down-regulate the expressions of MDR1, MRP1, and LRP mRNAs, as well as P-gp, MRP1, and LRP proteins related to drug resistance in A549/DDP cells. In vivo experiments also demonstrated that HIFU could reduce the size and mass of subcutaneously transplanted tumors produced by A549/DDP cells through mediating Cyclin-dependent and Bcl-2-dependent pathways. These results suggested that HIFU treatment could inhibit the proliferation of DDP-resistant lung cancer cells and might be a novel therapeutic method for patients with DDP resistance.

Ultrasonographic and clinicopathological features of pelvic yolk sac tumors in women: a single-center retrospective analysis.

Objectives: Yolk sac tumors (YSTs) are rare and highly malignant ovarian malignancies that have a very poor prognosis. The aim of this study is to delineate the ultrasound and clinicopathological features of female pelvic YSTs to better understand the disease. Methods: This study was a retrospective analysis of the clinicopathological and ultrasound imaging data from 16 YST patients who received treatment at our hospital between January 2012 and August 2023. Then, the ultrasound imaging characteristics were compared with pathological findings. Results: Among the 16 patients, various degrees of serum AFP increase were observed, and CA125 levels increased in 58.33% (7 out of 12) of patients. Thirteen patients (81.25%) had tumors located in ovary, two patients (12.5%) had tumors located in the sacrococcygeal region, and one patient (6.25%) had tumors located in the mesentery. Pathologically, nine patients presented with simple yolk sac tumors and seven with mixed germ cell tumors. According to the ultrasound manifestations, YST lesions can be classified into three types. (1) the cystic type, was diagnosed in two patients who presented with a large cystic mass with regular morphology and clear boundary and dense liquid within the cyst; and (2) the cystic-solid mixed type, was diagnosed in 4 patients. On 2D ultrasound, the lesions showed a cystic-solid mixed echo, and color Doppler showed a rich blood flow signal in the solid region and cystic separation. made up of four cases. (3) In ten patients with the solid type, 2D ultrasound showed solid uniform echoes with clear boundaries. The "fissure sign" was observed in the lesion. Color Doppler displayed rich blood flow in the solid part, and PW showed low to moderate resistance index of artery (RI:0.21-0.63). On contrast-enhanced ultrasound (CEUS), rapid and high enhancement in the solid part and cystic separation was observed in 2 patients. Conclusions: Combining ultrasound features with clinical information and tumor markers provides reliable clues for the diagnosis of YST. The application of two-dimensional ultrasound and CEUS combined with patient tumor marker levels can provide a robust reference for determining the necessity of fertility-preserving surgery and postoperative chemotherapy, which can improve clinical decision-making and patient consultation.

Benign Brenner tumor of the ovary: two-dimensional and contrast-enhanced ultrasound features-a retrospective study from a single center.

Objective: Benign Brenner tumor (BBT) is a rare ovarian tumor, and there are few discrete reports about its manifestation in an ultrasound. This study sought to investigate the two-dimensional (2D) and contrast-enhanced ultrasound (CEUS) features of this entity. Methods: This is a retrospective single-center study. The clinical manifestations, laboratory examination, and ultrasound data of 25 female patients with BBT were confirmed by pathology when they underwent 2D and/or CEUS examination at Ningbo First Hospital from January 2012 to June 2023. The ultrasound findings of the patients were analyzed using the terminology of the International Organization for the Analysis of Ovarian Tumor and were read by two senior sonographers who reached an agreement. Results: Among the all 25 patients, most of them were unilateral, and only one patient was bilateral. Thus, 26 lesions were found: 44.0% (11/25) were in the left and 52.0% (13/25) were in the right. Moreover, 53.84% (14/26) were solid lesions, 15.38% (4/26) were mixed lesions, and 26.92% (7/26) were cystic lesions. Among the solid-type patients, 42.85% (6/14) of the cases were with calcification. Upon laboratory examination, 12.0% (3/25) of the patients had high carbohydrate antigen 125 (CA-125) level, and 19.04% (4/21) of the patients had an elevated carbohydrate antigen724 (CA-724) level in the serum tumor markers. In the hormone test, 14.28% (3/21) were found to have a high postmenopausal estrogen level and 14.28%(3/21) were found to have a high level of follicle-stimulating hormone (FSH). One patient with complex manifestations and three with solid manifestations were examined by CEUS to observe the microcirculation perfusion of the tumor. One with solid and cystic separation was rapidly hyperenhanced and cleared, and the filling subsided faster than the uterus. The postoperative pathological diagnosis was benign Brenner tumor with mucinous cystadenoma. The other three cases were solid adnexal lesions, which showed isoenhancement on CEUS and disappeared slowly, synchronizing with the uterus. The CEUS results were considered as benign tumors and confirmed by pathology. Conclusions: BBT can show ovarian cystic, mixed cystic and solid type, and solid echo in 2D ultrasound. Unilateral ovarian fibrosis with punctate calcification is an important feature of BBT in 2D ultrasound. However, for solid adnexal masses and mixed cystic and solid masses with unclear diagnosis, if CEUS shows isoenhancement or hyperenhancement, the possibility of BBT cannot be excluded.

Contrast-enhanced ultrasonography findings of LAMNs with peritoneal and splenic metastases: a case report and literature review.

Low-grade appendiceal mucinous neoplasms (LAMNs) are rare appendiceal tumors that are primarily diagnosed using computed tomography(CT) enhancement and magnetic resonance imaging (MRI). Herein, we report the sonographic features, especially for contrast-enhanced ultrasound (CEUS), of a 70-year-old female with an unusual LAMN metastasizing to the peritoneum and spleen. The patient had a right pelvic mass 2 days prior to presentation. Two-dimensional (2D) ultrasound revealed a mixed cystic-solid mass in the right lower abdomen and spleen parenchyma; CEUS showed heterogeneous enhancement in both areas, suspected to be a mucinous mass. CT enhancement and MRI findings revealed concurrent findings. Histopathologically, LAMN lesions were confirmed in the appendix, spleen, and peritoneum of the specimens obtained during exploratory laparoscopy. No recurrences were reported at three years postoperatively. LAMN lesions may metastasize to abdominal organs, and imaging examinations are essential for diagnosis. This study presents major ultrasonography and CEUS findings for the diagnosis of LAMNs.

The value of contrast-enhanced ultrasonography in differential diagnosis of benign and malignant ovarian sex cord stromal tumors.

Background: Sex cord-stromal tumors (SCSTs) are uncommon neoplasms that are typically difficult to diagnose before surgery due to limited experience in their medical imaging. Contrast-enhanced ultrasonography (CEUS) can evaluate the microvessel density of tumors, and the microvessel density of malignant tumors is significantly greater than that of benign tumors, so this provides a method for CEUS to differentiate benign and malignant tumors. Methods: The CEUS diagnoses of 31 patients with pathologically confirmed SCSTs were retrospectively analyzed and compared to conventional ultrasound-based diagnoses. Based on the pathological results, the patients were divided into benign and non-benign groups. Using pathology as the gold standard, four-table data were used to evaluate the authenticity of conventional ultrasonography and CEUS. Results: Among these 31 SCST patients, only the size of the lesion and the stripy hypoenhancement on CEUS differed significantly between the benign group and the non-benign group (P<0.05). In the benign group (n=25), 22 patients showed sparse stripes of hypoenhancement, 1 showed no enhancement, and 2 showed hyperenhancement. In 5 cases of malignant SCSTs, 4 showed hyperenhancement (with non-enhanced areas inside the tumor), and 1 showed sparse strips of hypoenhancement; in 1 case of borderline SCST, the tumor showed uniform hyperenhancement. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rate of the conventional ultrasound diagnoses for the 31 SCST patients were 52.0%, 16.7%, 72.2%, 7.7%, and 45.2%, respectively. In relation to CEUS, sparse strips of hypoenhancement or no enhancement were valuable diagnostic criteria for diagnosing benign SCSTs. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rate of CEUS were 92.0%, 83.3%, 95.8%, 71.4%, and 90.3%, respectively. The accuracy of CEUS was higher than that of conventional US, and the difference was statistically significant (χ2=14.467, P=0.000). Conclusions: Sparse strips of hypoenhancement or no enhancement on CEUS are the characteristic manifestations of benign SCSTs, and hyperenhancement (with a non-enhanced area observable inside the mass) may be suggestive of malignant tumors. CEUS significantly improved the differentiation of benign and malignant SCSTs.

Imaging features of inflammatory pseudotumor-like follicular dendritic cell sarcoma of the spleen.

BACKGROUND: Inflammatory pseudotumor (IPT)-like follicular dendritic cell sarcoma (FDCS) is an extremely rare malignant neoplasm. METHODS: Retrospective analysis of imaging features of splenic IPT-like FDCS, including ultrasonography, computed tomography (CT), and magnetic resonance (MR) and contrast-enhanced imaging were performed. RESULTS: When the masses were small, the ultrasound images showed homogeneous hypoechoic signals, clear boundaries, and complete capsules. Abdominal plain CT scans showed equal density (easy to miss diagnosis), unclear boundaries, and no capsules. Magnetic resonance images (MRI) showed slightly shorter T1, slightly shorter T2, and clear boundaries. When the masses were large, the ultrasound images still showed clear boundaries and complete capsules, but the echoes of the masses were not uniform, and some of the masses showed dendritic hyperechoic centers. Abdominal plain CT scans showed irregular low densities in the center (unclear boundaries) and equal densities in the periphery. MRI showed short T1 and T2, but the central signals were mixed. When the mass was accompanied by extensive necrosis, abdominal plain CT scan showed mostly cystic lesions and slight calcifications in low density lesions. Contrast-enhanced CT showed only moderate enhancement in peripheral and septal areas. MRI showed that T1 and T2 were mainly mixed signals. Contrast-enhanced MR showed moderate enhancement of peripheral areas and septum. CONCLUSIONS: This is the first report to describe the IPT manifestations of the spleen (ultrasonography, CT, and MR). The diagnosis of IPT can be made by combining three imaging features.

Active targeting nano-scale bubbles enhanced ultrasound cavitation chemotherapy in Y1 receptor-overexpressed breast cancer.

Ultrasound cavitation therapy has attracted much attention in recent years because the cavitation of microbubbles can be leveraged to boost the infiltration of chemotherapeutic drugs into cancer tissues. For breast cancer therapy, most of the previously reported microbubbles lack specific targeting capacity and permeability. In this study, we have successfully fabricated Y1 receptor ligand (NPY)-modified bubbles, and examined their therapeutic efficacies as size-dependent functions with or without NPY targeting. To achieve this, four types of micro-scale bubbles (MBs or MBs-NPY) and nano-scale bubbles (NBs or NBs-NPY) were comprehensively evaluated. In vivo results indicated that the NBs-NPY group with doxorubicin (DOX) under ultrasound irradiation showed a high tumor suppression effect and a prolonged survival time. Furthermore, the NBs-NPY with DOX group exhibited minimal damage to mouse vital organs, which points to the considerable tolerance of the proposed nanosystem for efficacious breast cancer therapy. In summary, these findings suggest that the developed NPY-targeted NBs could have a broad application prospect in ultrasound cavitation chemotherapy of Y1 receptor-overexpressed breast cancer.

Retinal ganglion cells do not extend axons by default: promotion by neurotrophic signaling and electrical activity.

We investigate the signaling mechanisms that induce retinal ganglion cell (RGC) axon elongation by asking whether surviving neurons extend axons by default. We show that bcl-2 overexpression is sufficient to keep purified RGCs alive in the absence of any glial or trophic support. The bcl-2-expressing RGCs do not extend axons or dendrites unless signaled to do so by single peptide trophic factors. Axon growth stimulated by peptide trophic factors is remarkably slow but is profoundly potentiated by physiological levels of electrical activity spontaneously generated within embryonic explants or mimicked on a multielectrode silicon chip. These findings demonstrate that these surviving neurons do not constitutively extend axons and provide insight into the signals that may be necessary to promote CNS regeneration.

Folate receptor-targeted ultrasonic PFOB nanoparticles: Synthesis, characterization and application in tumor-targeted imaging.

In this study, we aimed to determine an effective strategy for the synthesis of folate receptor (FR) targeted-nanoparticles (FRNPs). The nanoparticles used as ultrasound contrast agents (UCAs) were composed of a liquid core of perfluorooctyl bromide (PFOB) liposome and a targeted shell chemically conjugated with folic acid (FA) and polyethylene glycol (PEG). This was done in order to avoid recognition and clearance by the mononuclear phagocyte system [also known as the reticuloendothelial system (RES)] and enhance the targeting capability of the nanoparticles to tumors overexpressing folate receptor (FR). The FRNPs exhibited an average particle size of 301±10.8 nm and surface potential of 39.1±0.43 mV. Subsequently, in vitro, FRNPs labeled with FITC fluorescence dye were visibly uptaken into the cytoplasm of FR-overexpressing cancer cells (Bel7402 and SW620 cells), whereas the A549 cells expressing relatively low levels of FR just bound with few FRNPs. These results demonstrated that FRNPs have a high affinity to FR-overexpressing cancer cells. Additionally, in in vivo experiments, FRNPs achieved a greater enhancement of tumor ultrasound imaging and a longer enhancement time in FR-overexpressing tumors and the Cy7-labeled FRNPs exhibited a relatively high tumor-targeted distribution in FR­overexpressing tumors. Targeted ultrasound and fluorescence imaging revealed that FRNPs have the ability to target FR-overexpressing tumors and ex vivo fluorescence imaging was then used to further verify and confirm the presence of FRNPs in tumor tissues with histological analysis of the tumor slices. On the whole, our data demonstrate that the FRNPs may prove to be a promising candidate for the early diagnosis for FR-overexpressing tumors at the molecular and cellular levels.

Shear wave elastography diagnosis of the diffuse sclerosing variant of papillary thyroid carcinoma: A case report.

The present study aimed to report the shear wave elastography (SWE) findings in a patient with the diffuse sclerosing variant of papillary thyroid carcinoma (DSVPTC). Since patients with DSVPTC may present with typical clinicopathological features and initially appear to have Hashimoto's thyroiditis, a thorough clinical evaluation and an early diagnosis are important. A 20-year-old female patient presented with a 1-month history of a neck mass and sore throat. Conventional ultrasound and SWE were performed using an AIXPLORER system with 14-5 MHz linear transducer. The patient had undergone total thyroidectomy and bilateral neck lymph node dissection, and an intraoperative pathology consultation to confirm the malignancy of lymph node metastasis. Pathological diagnosis was DSVPTC in both lobes, with lymph node metastases in the bilateral neck. The clinical presentation and serological findings were all indicative of Hashimoto's thyroiditis. Thyroid ultrasonography revealed diffuse enlargement of the both lobes, heterogenous echogenicity without mass formation, diffuse scattered microcalcifications and poor vascularization. SWE revealed stiff values of the thyroid: The mean stiffness was 99.7 kpa, the minimum stiffness was 59.1 kpa and the maximum stiffness was 180.1 kpa. The maximum stiffness of the DSVPTC (180.1 kpa) was higher compared with the diagnostic criteria of malignant thyroid nodules (65 kPa). SWE may be considered as a novel and valuable method to diagnose DSVPC.

Shear wave elastography and contrast-enhanced ultrasonography in the diagnosis of thyroid malignant nodules.

The aim of the present study was to evaluate the value of shear wave elastography (SWE) and contrast-enhanced ultrasonography (CEUS) in the diagnosis of thyroid malignant nodules. A total of 253 patients with 319 thyroid nodules were subjected to two-dimensional ultrasound (2DUS) and CEUS examinations prior to thyroidectomy between March, 2014 and December, 2015. Young's modulus value for each nodule on 2DUS and CEUS images were recorded. The sensitivity, specificity and accuracy of 2DUS, SWE and CEUS in the diagnosis of thyroid malignant nodules were assessed. The results demonstrated that, of the 319 nodules that were pathologically confirmed, 183 were malignant and 136 were benign. The area under the receiver operating characteristic curve as a result of SWE diagnosis was 0.77. When the threshold of the Young's modulus value was ≥27.65 kPa in the diagnosis of malignant thyroid nodules, SWE exhibited a sensitivity of 84.55% (115/136), a specificity of 84.15% (154/183) and an accuracy of 84.32% (269/319). US contrast imaging of malignant thyroid nodules revealed a major tendency for early hypoenhancement and hypoenhancement. CEUS exhibited a sensitivity of 87.5% (119/136), a specificity of 86.33% (158/183) and an accuracy of 86.83% (277/319) in the diagnosis of malignant thyroid nodules. Compared with 2DUS, SWE, CEUS and their combined use exhibited statistically significant differences in the diagnosis of thyroid malignant nodules in terms of sensitivity, specificity and accuracy (χ2=9.220,15.310 and 40.296, respectively; P=0.000); SWE or CEUS did not differ significantly in the diagnosis of thyroid malignant nodules in terms of sensitivity, specificity or accuracy (χ2=0.737;P=0.542); Compared with the use of SWE or CEUS alone, their combination exhibited statistically significant differences in the diagnosis of malignant thyroid nodules in terms of sensitivity, specificity and accuracy (χ2=12.264 and 6.939, respectively; P=0.000,0.005). In conclusion, the high accuracy of the combined use of SWE and CEUS in the diagnosis of malignant thyroid nodules is of great clinical value.

Heterojunction photovoltaics using printed colloidal quantum dots as a photosensitive layer.

We demonstrate a bilayer photovoltaic device consisting of a heterojunction between colloidal cadmium selenide (CdSe) quantum dots (QDs) and a wide band gap organic hole-transporting thin film of N,N'-diphenyl-N,N'-bis(3-methylphenyl)[1,1'-biphenyl]-4,4'-diamine (TPD) molecules. The active light-absorbing film of QDs is nondestructively printed onto TPD using microcontact stamping. Indium-tin-oxide (ITO) provides the top contact. The resulting device structure can accommodate different size QDs, produces an exceptionally large open circuit voltage (0.8 V) for an architecture with symmetric electrodes, and yields an internal quantum efficiency of 10% at the first QD absorption peak.