Fibroblast regulates angiogenesis in assembled oral cancer organoid: A possible role of NNMT.

OBJECTIVE: Tumour angiogenesis is affected by various cell types in the tumour microenvironment (TME), including cancer cells and cancer-associated fibroblasts (CAFs). Here, an assembled organoid model was generated to investigate the mechanism by which the TME regulates angiogenesis in oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Secretion of vascular endothelial growth factor-A (VEGFA) was analysed to compare the proangiogenic properties of OSCC cells and corresponding CAFs. Cell aggregates consisting of endothelial cells (ECs), CAFs and cancer cells were generated to construct assembled organoids. Nicotinamide N-methyltransferase (NNMT) was pharmacologically or genetically inhibited to block the activation of CAFs. ATAC-seq was employed to test the transcriptional network of fibroblasts overexpressing NNMT. RESULTS: Compared with cancer cells, CAFs secreted more VEGFA. Coculture with CAFs more effectively promoted the sprouting of ECs. Blockade of CAF activation via inhibition of NNMT drastically reduced the expression of CD31 in the assembled organoids. Overexpression of NNMT enhanced the transcription of genes related to angiogenesis in fibroblasts. Specifically, NNMT orchestrated the enrichment of the transcription factor JUNB at the promoter of VEGFA. CONCLUSIONS: We clarify that stromal NNMT enables the steady reproduction of angiogenesis in assembled oral cancer organoids, providing a novel target for exploiting antiangiogenic therapy.

Kaempferol attenuates inflammation in lipopolysaccharide-induced gallbladder epithelial cells by inhibiting the MAPK/NF-κB signaling pathway.

Kaempferol (KPR), a flavonoid compound found in various plants and foods, has garnered attention for its anti-inflammatory, antioxidant, and anticancer properties. In preliminary studies, KPR can modulate several signaling pathways involved in inflammation, making it a candidate for treating cholecystitis. This study aimed to explore the effects and mechanisms of KPR on lipopolysaccharide (LPS)-induced human gallbladder epithelial cells (HGBECs). To assess the impact of KPR on HGBECs, the HGBECs were divided into control, KPR, LPS, LPS + KPR, and LPS + UDCA groups. Cell viability and cytotoxicity were evaluated by MTT assay and lactate dehydrogenase (LDH) assay, respectively, and concentrations of KPR (10-200 µM) were tested. LPS-induced inflammatory responses in HGBECs were to create an in vitro model of cholecystitis. The key inflammatory markers (IL-1ß, IL-6, and TNF-α) levels were quantified using ELISA, The modulation of the MAPK/NF-κB signaling pathway was measured by western blot using specific antibodies against pathway components (p-IκBα, IκBα, p-p65, p65, p-JNK, JNK, p-ERK, ERK, p-p38, and p38). The cell viability and LDH levels in HGBECs were not significantly affected by 50 µM KPR, thus it was selected as the optimal KPR intervention concentration. KPR increased the viability of LPS-induced HGBECs. Additionally, KPR inhibited the inflammatory factors level (IL-1ß, IL-6, and TNF-α) and protein expression (iNOS and COX-2) in LPS-induced HGBECs. Furthermore, KPR reversed LPS-induced elevation of p-IκBα/IκBα, p-p65/p65, p-JNK/JNK, p-ERK/ERK, and p-p38/p38 ratios. KPR attenuates the LPS-induced inflammatory response in HGBECs, possibly by inhibiting MAPK/NF-κB signaling.

High-dose dual therapy versus bismuth-containing quadruple therapy for the eradication of Helicobacter pylori: A systematic review and meta-analysis.

OBJECTIVE: To update evidence-based data comparing the efficacy and safety of high-dose dual therapy (HDDT) and bismuth-containing quadruple therapy (BQT) in eradicating Helicobacter pylori infection through meta-analysis. METHODS: Multiple databases were systematically searched for randomized controlled trials (RCTs) published up to May 18, 2023. Dichotomous data were evaluated using risk ratio (RR) and 95% confidence interval (CI). Subgroup analysis, sensitivity analysis, risk of bias assessment, and quality of evidence evaluation were performed. RESULTS: Twenty RCTs containing 7891 subjects were included in the analysis. There was no statistically significant difference in H. pylori eradication rate between HDDT and BQT in the intention-to-treat (ITT) analysis (86.31% vs 84.88%; RR 1.02, 95% CI 1.00-1.04, P = 0.12). In the per-protocol (PP) analysis, the eradication rates for HDDT and BQT were 90.27% and 89.94%, respectively (RR 1.01, 95% CI 0.99-1.03, P = 0.44). Adverse events were significantly lower with HDDT than with BQT (RR 0.44, 95% CI 0.38-0.51, P < 0.00001). Patient adherence was significantly different between the two groups (RR 1.01, 95% CI 1.00-1.03, P = 0.02). Subgroup analysis based on antibiotic combinations within the BQT group showed a significantly higher eradication rate for HDDT than for BQT only when BQT used amoxicillin combined with clarithromycin (P = 0.0009). CONCLUSIONS: HDDT showed comparable efficacy with BQT for H. pylori eradication, with fewer adverse effects and higher compliance. Due to regional differences, antibiotic resistance rates, and combined BQT antibiotics, more studies are needed for further validation and optimization of HDDT.

Discovery of PXR agonists from Hypericum japonicum: A class of novel nonaromatic acylphloroglucinol-terpenoid adducts.

Pregnane X receptor (PXR) has been considered as a promising therapeutic target for cholestasis due to its crucial regulation in bile acid biosynthesis and metabolism. To search promising natural PXR agonists, the PXR agonistic activities of five traditional Chinese medicines (TCMs) with hepatoprotective efficacy were assayed, and Hypericum japonicum as the most active one was selected for subsequent phytochemical investigation, which led to the isolation of eight nonaromatic acylphloroglucinol-terpenoid adducts including seven new compounds (1 - 4, 5a, 5b and 6). Their structures including absolute configurations were determined by comprehensive spectroscopic, computational and X-ray diffraction analysis. Meanwhile, the PXR agonistic activities of aplenty compounds were evaluated via dual-luciferase reporter assay, RT-qPCR and immunofluorescence. Among them, compounds 1 - 4 showed more potent activity than the positive drug rifampicin. Furthermore, the molecular docking revealed that 1 - 4 were docked well on the PXR ligand binding domain and formed hydrogen bonds with amino acid residues Gln285, Ser247 and His409. This investigation revealed that H. japonicum may serve as a rich source of natural PXR agonists.

Identification of TAP1 as a T-cell related therapeutic target in gastric cancer by mediating oxalipliatin-related synergistic enhancement of immunotherapy.

BACKGROUND: Given the intricate molecular complexities and heterogeneity inherent in T-cell immunotherapy of gastric cancer (GC), elucidative T-cell-related biomarkers were imperative needed for facilitating the prediction of GC patient prognosis and identify potential synergistic therapeutic targets. METHODS: We conducted COX regression analysis in TISIDB, TCGA-STAD, and GEO databases to identify 19 GC T-cell-mediated sensitivity tumor killing (TTK) genes (key GCTTKs). Based on key GCTTKs, we constructed two TTK patterns and analyzed their metabolic pathways, mutation features, clinical data distribution, immune cell infiltration, and prognosis. LASSO regression was performed to develop a T-cell-mediated GC Prognosis (TGCP) model. We validated the TGCP model in GC patients. TAP1 was further selected for investigation of its biological functions and molecular mechanisms. We assessed the potential of TAP1 as a promising therapeutic target for GC using Patient-derived organoids (PDOs)-derived xenografts (PDOXs) models of GC. RESULTS: The TTK patterns display notable disparities. The TGCP model showcases its proficiency in predicting immune response efficacy, effectively distinguishes immunotherapy difference GC patients. Our findings find further confirmation in PDOX models, affirming TAP1 can enhance immunotherapy facilitated by PDL1 inhibitors. Furthermore, Oxaliplatin, by promoting TAP1 expression, augments PDL1 expression, thereby enhancing the efficacy of immunotherapy. CONCLUSIONS: We constructed a TGCP model, which demonstrates satisfactory predictive accuracy. Out of 9 prognostic genes, TAP1 was validated as a synergistic target for Oxaliplatin and PDL1 inhibitors, offering a genetic-level explanation for the synergy observed in GC treatment involving Oxaliplatin in combination with PDL1 inhibitors.

Impact of Microbubble Degradation and Flow Velocity on Subharmonic-aided Pressure Estimation (SHAPE): An Experimental Investigation.

OBJECTIVE: This study aimed to investigate the impact of microbubble degradation and flow velocity on Sub-Harmonic Aided Pressure Estimation (SHAPE), and to explore the correlation between subharmonic amplitude and pressure as a single factor. METHODS: We develop an open-loop vascular phantom platform system and utilize a commercial ultrasound machine and microbubbles for subharmonic imaging. Subharmonic amplitude was measured continuously at constant pressure and flow velocity to assess the impact of microbubble degradation. Flow velocity was varied within a range of 4-14 cm/s at constant pressure to investigate its relationship to subharmonic amplitude. Furthermore, pressure was varied within a range of 10-110 mm Hg at constant flow velocity to assess its isolated effect on subharmonic amplitude. RESULTS: Under constant pressure and flow velocity, subharmonic amplitude exhibited a continuous decrease at an average rate of 0.221 dB/min, signifying ongoing microbubble degradation during the experimental procedures. Subharmonic amplitude demonstrated a positive correlation with flow velocity, with a variation ratio of 0.423 dB/(cm/s). Under controlled conditions of microbubble degradation and flow velocity, a strong negative linear correlation was observed between pressure and subharmonic amplitude across different Mechanical Index (MI) settings (all R2 > 0.90). The sensitivity of SHAPE was determined to be 0.025 dB/mmHg at an MI of 0.04. CONCLUSION: The assessment of SHAPE sensitivity is affected by microbubble degradation and flow velocity. Excluding the aforementioned influencing factors, a strong linear negative correlation between pressure and subharmonic amplitude was still evident, albeit with a sensitivity coefficient lower than previously reported values.

Pitfalls of ultrasound for deep vein thrombosis of the lower extremities.

Venous ultrasound is the primary, widely accepted diagnostic tool to assess deep vein thrombosis (DVT) in the lower extremities. However, other focal lesions in the lower extremities can be identified on ultrasound. The sonographic appearance of these abnormalities may overlap the thrombosis, which included vascular tumors, Baker's cyst, hematoma, cancer thrombosis, and peripheral nerve tumors. This essay derives from cases diagnosed in our centers and published literature, with images available for illustrations, which may help to improve the clinical management of these findings.

Induction of therapeutic immunity and cancer eradication through biofunctionalized liposome-like nanovesicles derived from irradiated-cancer cells.

Immunotherapy has revolutionized the treatment of cancer. However, its efficacy remains to be optimized. There are at least two major challenges in effectively eradicating cancer cells by immunotherapy. Firstly, cancer cells evade immune cell killing by down-regulating cell surface immune sensors. Secondly, immune cell dysfunction impairs their ability to execute anti-cancer functions. Radiotherapy, one of the cornerstones of cancer treatment, has the potential to enhance the immunogenicity of cancer cells and trigger an anti-tumor immune response. Inspired by this, we fabricate biofunctionalized liposome-like nanovesicles (BLNs) by exposing irradiated-cancer cells to ethanol, of which ethanol serves as a surfactant, inducing cancer cells pyroptosis-like cell death and facilitating nanovesicles shedding from cancer cell membrane. These BLNs are meticulously designed to disrupt both of the aforementioned mechanisms. On one hand, BLNs up-regulate the expression of calreticulin, an "eat me" signal on the surface of cancer cells, thus promoting macrophage phagocytosis of cancer cells. Additionally, BLNs are able to reprogram M2-like macrophages into an anti-cancer M1-like phenotype. Using a mouse model of malignant pleural effusion (MPE), an advanced-stage and immunotherapy-resistant cancer model, we demonstrate that BLNs significantly increase T cell infiltration and exhibit an ablative effect against MPE. When combined with PD-1 inhibitor (α-PD-1), we achieve a remarkable 63.6% cure rate (7 out of 11) among mice with MPE, while also inducing immunological memory effects. This work therefore introduces a unique strategy for overcoming immunotherapy resistance.

Promotion of self-directed learning abilities among Chinese medical students through preparing for career calling and enhancing teaching competencies in medical education: a cross-sectional study.

BACKGROUND: Medical students face a heavy burden as they are tasked with acquiring a vast amount of medical knowledge within a limited time frame. Self-directed learning (SDL) has become crucial for efficient and ongoing learning among medical students. However, effective ways to foster SDL ability among Chinese medical students are lacking, and limited studies have identified factors that impact the SDL ability of medical students. This makes it challenging for educators to develop targeted strategies to improve students' SDL ability. This study aims to assess SDL ability among Chinese medical students and examine the effects of career calling and teaching competencies on SDL ability, as well as the possible mechanisms linking them. METHODS: Data were collected from 3614 respondents (effective response rate = 60.11%) using cross-sectional online questionnaires and analyzed using IBM SPSS Statistics 22.0. The questionnaire comprised a Demographic Characteristics Questionnaire, Self-directed Learning Ability Scale (Cronbach's alpha = 0.962), Teaching Competencies Scale, and Career Calling Scale. RESULTS: The average SDL ability score of Chinese medical students was 3.68 ± 0.56, indicating a moderate level of SDL ability. The six factors of the Self-directed Learning Ability Scale-self-reflection, ability to use learning methods, ability to set study plans, ability to set studying objectives, ability to adjust psychological state, and willpower in studying-accounted for 12.90%, 12.89%, 12.39%, 11.94%, 11.34%, and 8.67% of the variance, respectively. Furthermore, career calling was positively associated with SDL learning ability (ß = 0.295, p < 0.001), and SDL learning ability was positively associated with teaching competencies (ß = 0.191, p < 0.01). Simple slope analysis showed that when the level of teaching competencies was higher, the influence of career calling on SDL ability was stronger. CONCLUSIONS: Chinese medical students' SDL ability has room for improvement. Medical students could strengthen their willpower in studying by setting milestones goals with rewards, which could inspire their motivation for the next goals. Teachers should guide students to learn experience to improve students' reflective ability. Educators play a crucial role in bridging the gap between career calling education and SDL ability enhancement, highlighting the significance of optimal teaching competencies. Colleges should focus on strengthening teachers' sense of career calling and teaching competencies.

Small-Scale High-Pressure Hydrogen Storage Vessels: A Review.

Nowadays, high-pressure hydrogen storage is the most commercially used technology owing to its high hydrogen purity, rapid charging/discharging of hydrogen, and low-cost manufacturing. Despite numerous reviews on hydrogen storage technologies, there is a relative scarcity of comprehensive examinations specifically focused on high-pressure gaseous hydrogen storage and its associated materials. This article systematically presents the manufacturing processes and materials used for a variety of high-pressure hydrogen storage containers, including metal cylinders, carbon fiber composite cylinders, and emerging glass material-based hydrogen storage containers. Furthermore, it introduces the relevant principles and theoretical studies, showcasing their advantages and disadvantages compared to conventional high-pressure hydrogen storage containers. Finally, this article provides an outlook on the future development of high-pressure hydrogen storage containers.

Engineering Nanoplatforms for Theranostics of Atherosclerotic Plaques.

Atherosclerotic plaque formation is considered the primary pathological mechanism underlying atherosclerotic cardiovascular diseases, leading to severe cardiovascular events such as stroke, acute coronary syndromes, and even sudden cardiac death. Early detection and timely intervention of plaques are challenging due to the lack of typical symptoms in the initial stages. Therefore, precise early detection and intervention play a crucial role in risk stratification of atherosclerotic plaques and achieving favorable post-interventional outcomes. The continuously advancing nanoplatforms have demonstrated numerous advantages including high signal-to-noise ratio, enhanced bioavailability, and specific targeting capabilities for imaging agents and therapeutic drugs, enabling effective visualization and management of atherosclerotic plaques. Motivated by these superior properties, various noninvasive imaging modalities for early recognition of plaques in the preliminary stage of atherosclerosis are comprehensively summarized. Additionally, several therapeutic strategies are proposed to enhance the efficacy of treating atherosclerotic plaques. Finally, existing challenges and promising prospects for accelerating clinical translation of nanoplatform-based molecular imaging and therapy for atherosclerotic plaques are discussed. In conclusion, this review provides an insightful perspective on the diagnosis and therapy of atherosclerotic plaques.

Molecular basis of Gabija anti-phage supramolecular assemblies.

As one of the most prevalent anti-phage defense systems in prokaryotes, Gabija consists of a Gabija protein A (GajA) and a Gabija protein B (GajB). The assembly and function of the Gabija system remain unclear. Here we present cryo-EM structures of Bacillus cereus GajA and GajAB complex, revealing tetrameric and octameric assemblies, respectively. In the center of the complex, GajA assembles into a tetramer, which recruits two sets of GajB dimer at opposite sides of the complex, resulting in a 4:4 GajAB supramolecular complex for anti-phage defense. Further biochemical analysis showed that GajA alone is sufficient to cut double-stranded DNA and plasmid DNA, which can be inhibited by ATP. Unexpectedly, the GajAB displays enhanced activity for plasmid DNA, suggesting a role of substrate selection by GajB. Together, our study defines a framework for understanding anti-phage immune defense by the GajAB complex.

[Prediction of Ozone Pollution in Sichuan Basin Based on Random Forest Model].

To study the long-term variation in ozone (O3) pollution in Sichuan Basin,the spatiaotemporal distribution of O3 concentrations during 2017 to 2020 was analyzed using ground-level O3 concentration data and meteorological observation data from 18 cities in the basin. The dominant meteorological factors affecting the variation in O3 concentration were screened out,and a prediction model between meteorological factors and O3 concentration was constructed based on a random forest model. Finally,a prediction analysis of O3 pollution in the Sichuan Basin urban agglomeration during 2020 was carried out. The results showed that:① O3 concentrations displayed a fluctuating trend during the period from 2017 to 2020,with a downward trend in 2019 and a rebound in 2020. ② The fluctuating trend of O3 concentration was significantly influenced by relative humidity,daily maximum temperature,and sunshine hours,whereas wind speed,air pressure,and precipitation had less impact. The linear relationships between meteorological factors were different. Air pressure was negatively correlated with other meteorological factors,whereas the remaining meteorological factors had a positive correlation. ③ The goodness of fit statistics (R2) between the predicted and actual values of the O3 prediction model constructed based on random forest demonstrated a strong predictive performance and ability to accurately forecast the long-term daily variations in O3 concentration. The random forest O3 prediction model exhibited excellent stability and generalization capability. ④ The prediction analysis of O3 concentrations in 18 cities in the basin showed that the explanation rate of variables in the prediction model reached over 80% in all cities (except Ya'an),indicating that the random forest model predicted the trend of O3 concentration accurately.

Nickel-catalysed regio- and stereoselective hydrocyanation of alkynoates and its mechanistic insights proposed by DFT calculations.

We have developed a nickel-catalysed regio- and stereoselective hydrocyanation of alkynoates that gives syn-ß-cyanoalkenes. DFT calculations suggest that a favored transition state promotes Cα-H bond formation for determining regio- and stereoselectivity of the products.

Self-assembly of a AuNPs/Ti3C2 MXene hydrogel for cascade amplification of microRNA-122 biosensing.

A three-dimensional (3D) self-assembled AuNPs/Ti3C2 MXene hydrogel (AuNPs/Ti3C2 MXH) nanocomposite was prepared for the fabrication of a novel microRNA-122 electrochemical biosensor. The 3D hydrogel structure was gelated from two-dimensional MXene nanosheets with the assistance of graphite oxide and ethylenediamine. MXene hydrogels supported the in situ formation of Au nanoparticles (AuNPs) that predominantly exploring the (111) facet, and these AuNPs are utilized as carriers for hairpin DNA (hpDNA) probes, facilitating DNA hybridization. MXene acted as both a reductant and stabilizer, significantly improving the electrochemical signal. In addition, the conjugation of PAMAM dendrimer-encapsulated AuNPs and H-DNA worked as an ideal bridge to connect targets and efficient electrochemical tags, providing a high amplification efficiency for the sensing of microRNA-122. A linear relationship between the peak currents and the logarithm of the concentrations of microRNA-122 from 1.0 × 10-2 to 1.0 × 102 fM (I = 1.642 + 0.312 lgc, R2 = 0.9891), is obtained. The detection limit is  0.8 × 10-2 fM (S/N = 3). The average recovery for human serum detection ranged from 97.32 to 101.4% (RSD < 5%).

Hydrazine-Assisted Synthesis, Structures, Photoelectricity, and Photocatalysis of Ternary Mercury-Tellurostannate Hybrids with Transition-Metal Complexes.

Tellurostannates are traditionally prepared by multistep reactions using the tellurides SnTe, SnTe2, K4SnTe4, or A6SnTe6 (A = K, Rb, or Cs) as precursors, which are usually prepared by the molten reaction of alkali metals Sn and Te under harsh synthetic conditions. Differently, ternary Hg-tellurostannate hybrids [Mn(en)3]HgSnTe3(Te2) (1) (en = ethylenediamine), [Mn(dien)2]HgSnTe3(Te2) (2), and [Fe(dien)2]HgSnTe3(Te2) (3) (dien = diethylenetriamine) were synthesized by one-pot reactions using Sn and Te powders as starting materials in the presence of hydrazine under mild solvothermal conditions. In 1, HgTe3 and SnTe4 units are joined via Te-sharing to form a 1-D polymeric chain [HgSnTe3(Te2)]n2n-, while the [HgSnTe3(Te2)]n2n- chains in 2 and 3 are composed of HgTe4 and SnTe4 units. The common feature of the [HgSnTe3(Te2)2-]n chains in 1-3 is that they are constructed by both the telluride anion Te2- and the polytelluride anion Te22-. 1-3 exhibited strong photocurrent responses with current densities of 5.26, 3.38, and 3.94 µA cm-2, respectively. They showed effective photocatalytic activities for methylene blue degradation with degradation ratios in the range of 85.3-94.6% after light irradiation for 80 min. Investigation of the photocatalytic mechanism showed that •O2- radicals and h+ holes were the main active substances in the photodegradation.

Peripheral Control of the Assembly and Chirality of Anion-Based Octanuclear Cubes by Cation-π Networks.

Self-assembly of sophisticated polyhedral cages has drawn much attention because of their elaborate structures and potential applications. Herein, we report the anion-coordination-driven assembly of the first A8L12 (A = anion, L = ligand) octanuclear cubic structures from phosphate anion and p-xylylene-spaced bis-bis(urea) ligands via peripheral templating of countercations (TEA+ or TPA+). By attaching terminal aryl rings (phenyl or naphthyl) to the ligand through a flexible (methylene) linker, these aryls actively participate in the formation of plenty of "aromatic pockets" for guest cation binding. As a result, multiple peripheral guests (up to 22) of suitable size are bound on the faces and vertices of the cube, forming a network of cation-π interactions to stabilize the cube structure. More interestingly, when chiral ligands were used, either diastereomers of mixed Λ- and Δ-configurations (with TEA+ countercation) for the phosphate coordination centers or enantiopure cubes (with TPA+) were formed. Thus, the assembly and chirality of the cube can be modulated by remote terminal groups and peripheral templating tetraalkylammonium cations.

Methods, Mechanisms, and Application Prospects for Enhancing Extracellular Vesicle Uptake.

Extracellular vesicles (EVs) are considered to be a new generation of bioinspired nanoscale drug delivery systems due to their low immunogenicity, natural functionality, and excellent biocompatibility. However, limitations such as low uptake efficiency, insufficient production, and inhomogeneous performance undermine their potential. To address these issues, numerous researchers have put forward various methods and applications for enhancing EV uptake in recent decades. In this review, we introduce various methods for the cellular uptake of EVs and summarize recent advances on the methods and mechanisms for enhancing EV uptake. In addition, we provide further understanding regarding enhancing EV uptake and put forward prospects and challenges for the development of EV-based therapy in the future.

Methylation enables the use of fluorine-free ether electrolytes in high-voltage lithium metal batteries.

Lithium metal batteries represent a promising technology for next-generation energy storage, but they still suffer from poor cycle life due to lithium dendrite formation and cathode cracking. Fluorinated solvents can improve battery longevity by improving LiF content in the solid-electrolyte interphase; however, the high cost and environmental concerns of fluorinated solvents limit battery viability. Here we designed a series of fluorine-free solvents through the methylation of 1,2-dimethoxyethane, which promotes inorganic LiF-rich interphase formation through anion reduction and achieves high oxidation stability. The anion-derived LiF interphases suppress lithium dendrite growth on the lithium anode and minimize cathode cracking under high-voltage operation. The Li+-solvent structure is investigated through in situ techniques and simulations to draw correlations between the interphase compositions and electrochemical performances. The methylation strategy provides an alternative pathway for electrolyte engineering towards high-voltage electrolytes while reducing dependence on expensive fluorinated solvents.