Suspension Injection Research Articles

Targeted axillary dissection using carbon marking for patients with node-positive breast cancer following neoadjuvant therapy (TADCOM): study protocol for a prospective, multicenter, randomized controlled trial

BackgroundNeoadjuvant chemotherapy (NAC) for breast cancer enables pathological complete response (pCR) in patients initially diagnosed with axillary lymph node metastases, potentially obviating the need for axillary lymph node dissection (ALND). Current targeted axillary dissection (TAD) techniques, guided by traditional tissue markers placed prior to NAC, face challenges such as marker loss and high costs. Carbon nanoparticle suspension injection (CNSI) offers a stable and reliable alternative for marking, which could enhance the TAD procedure. This study aims to evaluate the feasibility and accuracy of different TAD strategies using CNSIs and to explore their clinical utility in locally advanced breast cancer.MethodsThis prospective, multicenter, randomized controlled trial will enroll 126 biopsy-proven breast cancer patients with suspicious axillary lymph node metastases (cN1-2a) who achieve ycN0 status following NAC. Participants will be randomized in a 1:1:1 ratio to undergo TAD guided by: [1] conventional tissue clips (CG-TAD); [2] CNSI lymph node marking (CN-LNM); or [3] peritumoral CNSI mapping (PCN-MAP). Primary endpoints include retrieval rate of marked lymph nodes, number of sentinel and marked lymph nodes, concordance rates, and complication rates. Secondary endpoints encompass regional and distant recurrence rates, survival outcomes, surgical duration, postoperative complications, quality of life scores, and margin status in breast-conserving surgery. Statistical analyses will adhere strictly to the CONSORT guidelines.DiscussionThis study aims to evaluate the feasibility and accuracy of CNSI for targeted axillary dissection in breast cancer patients following neoadjuvant chemotherapy and to explore its clinical significance in reducing surgical complications and costs, as well as improving surgical precision.Trial registrationClinicaltrials.gov, NCT04744506, Registered 27 December 2020, Updated 24 September 2024. Protocol Version Ver 1.2, 17/9/2024.

Improving transient gene expression and agroinfiltration‐based transformation effectiveness in Indonesian orchid Phalaenopsis amabilis (L.) Blume

Transient gene expression is an approach used to study transient genes across various species, with infiltration by Agrobacterium tumefaciens (agroinfiltration) being a commonly used method. Agroinfiltration offers a simple and effective means of delivering transgenes into the plant genome. An alternative method for enhancing the quality and productivity of orchids as ornamental plants is genetic modification through agroinfiltration. Although Agrobacterium‐mediated genetic transformation by immersion has been used on the Phalaenopsis amabilis (L.) Blume species of orchid, transformation efficiency using the immersion technique remains relatively low and the method itself is challenging due to its requirement for aseptic handling. The application of agroinfiltration in P. amabilis has not previously been reported. This study investigates the impact of the injection site, acetosyringone concentration, bacterial density (OD600), and injection volume to determine the optimum conditions for agroinfiltration on P. amabilis. The results demonstrated that injection site had a noticeably distinct impact on transformation effectiveness, with the abaxial position of the leaf being the optimal site for Agrobacterium culture suspension injection. While adjustments in acetosyringone concentration, bacterial density (OD600), and injection volume did not significantly affect transformation efficiency, they did influence the peak time of GFP fluorescence. Acetosyringone at a concentration of 200 µM, an OD600 of 1.0 for Agrobacterium culture, and an injection volume of 500 µL effectively accelerated GFP expression duration.

Fluorine-free superhydrophobic surfaces by atmospheric pressure plasma deposition of silazane-based suspensions

Atmospheric plasma is used to deposit superhydrophobic fluorine-free thin films onto a substrate. In this process, a suspension of micron size silica particles in a silazane based precursor is deposited in a single step using a dielectric barrier discharge plasma jet moving above the substrate. Thanks to an optimized configuration between the suspension injection and the plasma jet, the silazane precursor can be polymerized on the substrate surface but also, on silica particles to form additional micro size particles. The experimental parameters for optimal deposition are discussed, with emphasis on those leading to the formation of this dual roughness surface caused by the arrangement of both silica particles and particles generated from the precursor plasma polymerization. The combination of these two different length scales for the roughness leads to a decreased wettability of the coated substrate and a water contact angle larger than 150°.

Damage mechanism of proppant and conductivity reduction post fracturing in unconventional reservoirs

To investigate the impact of proppant embedding and crushing damage on the conductivity in unconventional oil and gas development, experiments on long-term conductivity under suspension injection of proppant were conducted on shale and tight sandstone samples. Based on elastic contact mechanics theory, finite element software (Abaqus) was secondarily developed to globally embed proppant meshes with cohesive elements, analyzing the dynamic changes involving proppant embedding, deformation, and crushing under different closure pressures. The results indicated that the conductivity of fractures is highly sensitive to closure pressure. When closure pressure increases to 40 MPa, the conductivity of shale damage exceeds 60 % compared to 10 MPa. Larger proppants and shale reservoirs accelerate the decline in conductivity significantly, compared to tight sandstone. Combined with laser scanning and fractal dimension identification, the roughness of shale fracture (JRC48) was found to be much greater than that of tight sandstone (JRC37), leading to significantly higher stress concentration between proppants and shale, resulting in a smaller crushing ratio. Additionally, the deformation of shale and contacting proppant is significantly greater than in sandstone, resulting in a rapid decline in shale oil production. These findings provide theoretical guidance for ensuring effective inflow near oil wells, necessitating optimization of proppant injection sequence and placement concentration.

Development of Neural Cells and Spontaneous Neural Activities in Engineered Brain-Like Constructs for Transplantation.

Stem cell transplantation has demonstrated efficacy in treating neurological disorders by generating functional cells and secreting beneficial factors. However, challenges remain for current cell suspension injection therapy, including uncontrollable cell distribution, the potential for tumor formation, and limited ability to treat spatial defects. Therefore, implants with programmable cell development, tailored 3D structure, and functionalized biomaterials have the potential to both control cell distribution and reduce or heal spatial defects. Here, a biomimetic material system comprising gelatin, alginate, and fibrinogen has been developed for neural progenitor cell constructs using 3D printing. The resulting constructs exhibit excellent formability, stability, and developmental functions in vitro, as well as biocompatibility and integration into the hippocampus in vivo. The controllability, reproducibility, and material composition of the constructs show potential for use in personalized stem cell-based therapies for defective neurological disorders, neural development research, disease modeling, and organoid-derived intelligent systems.

Thick Columnar-Structured Thermal Barrier Coatings Using the Suspension Plasma Spray Process

Higher operating temperatures for gas turbine engines require highly durable thermal barrier coatings (TBCs) with improved insulation properties. A suspension plasma spray process (SPS) had been developed for the deposition of columnar-structured TBCs. SPS columnar TBCs are normally achieved at a short standoff distance (50.0 mm–75.0 mm), which is not practical when coating complex-shaped engine hardware since the plasma torch may collide with the components being sprayed. Therefore, it is critical to develop SPS columnar TBCs at longer standoff distances. In this work, a commercially available pressure-based suspension delivery system was used to deliver the suspension to the plasma jet, and a high-enthalpy TriplexPro-210 plasma torch was used for the SPS coating deposition. Suspension injection pressure was optimized to maximize the number of droplets injected into the hot plasma core and achieving the best particle-melting states and deposition efficiency. The highest deposition efficiency of 51% was achieved at 0.34 MPa injection pressure with a suspension flow rate of 31.0 g/min. With the optimized process parameters, 1000 μm thick columnar-structured SPS 8 wt% Y2O3-stabilized ZrO2 (8YSZ) TBCs were successfully developed at a standoff distance of 100.0 mm. The SPS TBCs have a columnar width between 100 μm and 300 μm with a porosity of ~22%. Furnace cycling tests at 1125 °C showed the SPS columnar TBCs had an average life of 1012 cycles, which is ~2.5 times that of reference air-plasma-sprayed dense vertically cracked TBCs with the same coating thickness. The superior durability of the SPS columnar TBCs can be attributed to the high-strain-tolerant microstructure. SEM cross-section characterization indicated the failure of the SPS TBCs occurred at the ceramic top coat and thermally grown oxide (TGO) interface.

A facile spinning approach towards the continuous production of aligned nanocellulose films

In this work, we present an alternative approach to cellulose nanofibril film (CNF) production, taking inspiration from the wet spinning of fibers to wet spin films. During the spinning process, a CNF suspension is injected into a coagulation bath, where the partially aligned CNF network is locked. The CNF alignment of the dry films is then detected by wide angle X-ray scattering (WAXS). The comparison between the ultimate strengths and strengths at breaks of the films produced with different process parameters, including the suspension injection rate, bath pH, and bath flow rate, indicated no significant change in mechanical properties, suggesting a reliable and constant outcome for large-scale film fabrication. Furthermore, the produced films demonstrated high total light transmittance of 93 % at the wavelength of 550 nm, making them suitable for optoelectronic applications. Polarized optical microscopy revealed that even a low degree of CNF alignment can lead to anisotropic optical properties. Moreover, an anisotropic response to humidity was observed, in which the films preferentially bend in the perpendicular direction of the CNF orientation, thus opening a way for humidity-driven actuators.

Effect of carbon nanoparticle suspension injection versus indocyanine green tracer in guiding lymph node dissection during radical gastrectomy (FUTURE-01): a randomized clinical trial.

Carbon nanoparticle suspension injection (CNSI) and indocyanine green (ICG) have both been applied intraoperatively to facilitate lymphatic mapping and postoperatively to sort lymph nodes (LNs) in gastric cancer patients. However, no study has compared the two tracers in gastric cancer patients. This prospective randomized controlled trial was conducted from January 2022 to March 2023. Patients with potentially resectable gastric cancer (cT1-4a N0/+ M0) were randomized to the CNSI or ICG group. This study enrolled 96 patients. Ninety patients were in the modified intention-to-treat population, including 46 patients (32 males and 14 females; mean [SD] age, 57.4 [9.4] years) in the CNSI group and 44 patients (31 males and 13 females; mean [SD] age, 60.8 [8.8] years) in the ICG group. The mean (SD) number of retrieved LNs was 69.8 (21.9) and 53.6 (17.2) in the CNSI and ICG groups, respectively (P<0.001). The mean (SD) number of retrieved micro-LNs was 19.9 (13.3) and 11.6 (9.9) in the CNSI and ICG groups, respectively (P=0.001). The mean (SD) number of metastatic LNs was 8.1 (11.9) and 5.2 (9.2) in the CNSI and ICG groups, respectively (P=0.19). Compared with ICG, CNSI can increase the number of LNs detected, especially micro-LNs. Both tracers have high diagnostic value for detecting metastatic LNs. CNSI-guided lymphography may be a superior method for improving the accuracy of LN dissection.

Applying colloidal silica suspensions injection and sequential gelation to block vertical water flow in well annulus: laboratory testing on rheology, gelation, and injection

We evaluated the application of silica suspension injection and sequential gelation to block vertical water flow in the annuli of long-screened wells. First, we studied the viscosity, rheological behavior, and gelation performance of colloidal silica suspensions in batch tests. Then, we tested the injection of silica suspensions and the water flow blocking efficiency of the later formed silica gel in column and bench-scale sandbox experiments. Micron-sized fumed powder silica suspensions and nanosized silica suspensions recovered from geothermal fluids were tested in this work. Fumed silica suspensions showed shear thinning, while nanosized silica suspensions exhibited Newtonian flow behavior. During the gelation process, the nanosized silica suspension changed from a Newtonian fluid to a shear thinning fluid while increasing its overall viscosity. At comparable concentrations, the nanosized silica suspensions have much lower viscosity than that of the fumed silica suspensions. Increases in the Na+ concentration and silica particle concentration in these suspensions shortened the gelation time. Silica suspension gelation in sand columns completely blocked the water flow and sustained the injection pressure up to 50 psig (344.7 kPa). A silica suspension was successfully injected into the target zone in the annulus of a bench-scale sandbox mimicking long-screened wells in the field. The silica gel formed in the annulus effectively blocked chemical transport through the gelled zone. Our research reveals that a process using silica suspension injection and sequential gelation technology is promising for blocking the vertical water flow and chemical transport through the filter pack in targeted zones within the annulus of long-screened well systems.

Abstract PO2-23-06: Clinical study of stained region lymph node biopsy (SrLNB) in axillary surgery after neoadjuvant systemic therapy in patients with axillary lymph node positive breast cancer

Abstract Background The probability of axillary lymph node converting from positive to negative after neoadjuvant systemic therapy (NST) for breast cancer patients is approximately 40%. A variety of axillary lymph node biopsy surgeries based on sentinel lymph node biopsy (SLNB) can help to omit axillary lymph node dissection (ALND). The common disadvantages, however, are mainly the restrictions, such as the need for strict regulation of the use of radiotracers, the high number of retrieved lymph nodes required, and the need to purchase ancillary equipment. The more restrictions there are, the more they limit the spread and availability of the technique and, more importantly, reduce the number of patients who will benefit. In fact, for patients with metastatic lymph nodes, the sentinel lymph nodes must be included in the lymph nodes that have metastasized. If these metastatic lymph nodes can be accurately marked and precisely retrieved after NST, it is possible to assess whether the axillary lymph nodes are converted from positive to negative without the need for SLNB. Materials and methods Breast cancer patients with pathologically confirmed axillary lymph node metastases who were receiving NST were recruited for this study. Before NST, carbon nanoparticles suspension injections were injected into the cortex of the pathologically confirmed metastatic lymph node to stain the region where the metastatic lymph node was located. The lymph nodes in the stained region were retrieved by stained region lymph node biopsy (SrLNB) during the axillary surgery, followed by ALND, without the use of SLNB. Finally, the identification rate and false-negative rate (FNR) of SrLNB were statistically analyzed according to pathology data. Results A total of 159 patients were successfully enrolled in this study between September 24, 2020 and December 2, 2022, with an axillary pCR rate of 40.9% (65/159). The identification rate of SrLNB was 100% (159/159), with an overall FNR of 5.3% (5/94). Subgroup analysis revealed that in the subgroups of 1, 2, 3 and ≥4 SrLN, the FNR was 0%, 0%, 0% and 8.9% (5/56), respectively, whereas in the cN1, cN2 and cN3 subgroups the FNR was 7.7% (3/39), 2.6% (1/38) and 5.9% (1/17), respectively. The FNR indexes were within the safety threshold of 10% in all subgroups. Conclusion SrLNB has a high identification rate and a low FNR and is useful for screening patients with positive to negative axillary lymph nodes for omitting ALND. srLNB requires only the use of an affordable and radiation-free carbon nanoparticles suspension injection for marking, making the whole technique simpler and easier to disseminate. The data from this study also suggest that SLNB may not be mandatory for axillary biopsy in patients with positive axillary lymph nodes undergoing NST. Table 1. General characteristics of enrolled patients. Table 2. Analysis of factors affecting axillary pCR rates. Table 3. Analysis for the FNR of SrLNB. Citation Format: Jue Wang, Rui Chen, Cuiying Li, Hailing Zha, Qiannan Zhu, Lifeng Huang, Xiaoming Zha. Clinical study of stained region lymph node biopsy (SrLNB) in axillary surgery after neoadjuvant systemic therapy in patients with axillary lymph node positive breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-23-06.

Clinically approved carbon nanoparticles for enhanced photothermal-immunotherapy toward cancer metastasis

The development of new biomedical applications of approved drugs has several advantages in drug translation. In this study, carbon nanoparticle suspension injection (CNSI), clinically approved for lymph node tracer in China, is explored as a photothermal conversion agents for the treatment of metastatic cancer. Metastasis commonly through lymphatic circulation accounts for the principal cause of death in cancer patients. Up to now, immunotherapy has been already used clinically for metastatic cancer. However, the suppressive tumor immune microenvironment limits the effectiveness of immunotherapy. Herein, we use the photothermal effect of CNSI under near-infrared (NIR) irradiation to eliminate primary tumor and induce the immunogenic cell death (ICD). Further, CNSI under irradiation combined with aPD-1 spur immune response and inhibit the growth of distal tumors. Except for the primary tumor, phototherapy was used to treat metastatic lymph nodes synchronously, which can not only eradicate cancer cells, but also directly activate the immune response inside the lymph nodes. Combining with aPD-1 further enhance the anti-tumor effect to block lymphatic metastases and inhibit lung metastases. This study shows that the carbon nanoparticles have potential clinical application prospects for the treatment of tumor metastasis.

Tailoring the porosity level of the suspension plasma sprayed coatings using a dual suspension injection system

This study investigated the feasibility of tailoring the porosity in suspension plasma sprayed (SPS) coatings using a dual suspension injection system. Two titanium dioxide water-based suspensions with different particle sizes were injected into the plasma jet through two injectors located at different radial distances from the exit of the plasma torch. By varying the spray parameters, the fraction of unmelted particles in the coatings coming from the injector located farther from the torch changed. The total porosity was evaluated to range from approximately 16 % to 36 %, and the variation was related principally to the gaps between the unmelted particles. Among the selected spray parameters, the suspension feed rate and distance between the injectors were found to have the most significant effect on increasing the porosity. The samples were analyzed using SEM, XRD, and Raman spectroscopy.

Temperature-Sensitive Nanocarbon Hydrogel for Photothermal Therapy of Tumors.

Intelligent hydrogels continue to encounter formidable obstacles in the field of cancer treatment. A wide variety of hydrogel materials have been designed for diverse purposes, but materials with satisfactory therapeutic effects are still urgently needed. Here, we prepared an injectable hydrogel by means of physical crosslinking. Carbon nanoparticle suspension injection (CNSI), a sentinel lymph node imaging agent that has been widely used in the clinic, with sodium β-glycerophosphate (β-GP) were added to a temperature-sensitive chitosan (CS) hydrogel (CS/GP@CN) as an agent for photothermal therapy (PTT). After evaluating the rheological, morphological, and structural properties of the hydrogel, we used 4T1 mouse breast cancer cells and B16 melanoma cells to assess itsin vitroproperties. Then, we intratumorally injected the hydrogel into BALB/c tumor-bearing mice to assess the in vivo PTT effect, antitumor immune response and the number of lung metastases. Surprisingly, this nanocarbon hydrogel called CS/GP@CN hydrogel not only had good biocompatibility and a great PTT effect under 808nm laser irradiation but also facilitated the maturation of dendritic cells to stimulate the antitumor immune response and had an extraordinary antimetastatic effect in the lungs. Overall, this innovative temperature-sensitive nanocarbon hydrogel, which exists in a liquid state at room temperature and transforms to a gel at 37 °C, is an outstanding local delivery platform with tremendous PTT potential and broad clinical application prospects.

Electroacupuncture combined with bone marrow mesenchymal stem cell transplantation promotes repair of thin endometrium by regulating SDF-1/CXCR4 signaling

It is to explore, based on stromal cell derived factor 1 (SDF-1)/CXC chemokine receptor 4 (CXCR4) signal axis, whether the electroacupuncture (EA) combined with bone marrow mesenchymal stem cells (BMSCs) transplantation can promote thin endometrium regeneration and improve endometrial receptivity, so as to further study its mechanisms underlying improvement of promoting BMSCs homing to repair thin endometrium. Thirty matured female SD rats were randomly divided into normal control , model , BMSCs transplantation (BMSCs), BMSCs+AMD3100 (a specific antagonist of CXCR4, BMSCs+AMD3100), BMSCs+EA, and BMSCs+EA+AMD3100 groups, with 5 rats in each group. The thin endometrial model was established by intrauterine injection of 95% ethanol during the period of estrus. Rats of the model group received intravenous injection of PBS solution (tail vein) on day 1, 3 and 7 of modeling and intraperitoneal injection of normal saline once daily for 3 estrous cycles. Rats of the BMSCs group received intravenous injection of BMSCs suspension on day 1,3 and 7 of modeling, and those of the BMSCs+EA group received BMSCs transplantation and EA stimulation. EA (2 Hz/15 Hz, 1 mA) was applied to "Guanyuan" (CV4) and bilateral "Sanyinjiao"(SP9), "Zigong" (EX-CA1) for 15 min, once daily for 3 estrous cycles. Rats of the BMSCs+AMD3100 group received intravenous injection of BMSCs suspension (1×106/mL) and intraperitoneal injection of AMD3100 (5 mg/kg), and those of the BMSCs+EA+AMD3100 group received administration of BMSCs, AMD3100 and EA, with both groups being once daily for 3 estrous cycles. H.E. staining was used to observe histopathological changes of endometrium tissues, and immunohistochemistry was used to detect the expressions of cytokeratin (CK19) and vimentin in endometrium (for evaluating the damage and repair of endometrium). The expression levels of homeobox A10 (HOXA10), leukemia inhibitory factor (LIF), SDF-1 and CXCR4 proteins were detected by Western blot, and those of SDF-1 and CXCR4 mRNAs in the endometrium detected by real-time PCR. In comparison with the normal control group, the number of endometrial glands, the immunoactivity of CK19 and vimentin, the expression leve-ls of HOXA10, LIF and CXCR4 proteins and CXCR4 mRNA were significantly down-regulated (P<0.01), and the expression levels of SDF-1 protein and mRNA significantly up-regulated (P<0.05) in the model group. Compared with the model group, the number of endometrial glands, the immunoactivity of CK19 and vimentin, and the expression levels of HOXA10, LIF, CXCR4 proteins and CXCR4 mRNA in the BMSCs group, and the number of endometrial glands, the immunoactivity of CK19 and vimentin, the expression levels of HOXA10, LIF, CXCR4 proteins and CXCR4 mRNA, and SDF-1 protein and mRNA in the BMSCs+EA group were significantly up-regulated (P<0.05, P<0.01). Compared to the BMSCs group, the number of endometrial glands, and the expression levels of LIF, CXCR4 proteins and CXCR4 mRNA in the BMSCs+EA group were up-regulated (P<0.01, P<0.05)； the number of endometrial glands, the immunoactivity of CK19 and vimentin, the expression levels of HOXA10, LIF, CXCR4 proteins and CXCR4 mRNA in the BMSCs+AMD3100 group were down-regulated (P<0.01). Compared to the BMSCs+EA group, the number of endometrial glands, the immunoactivity of CK19 and vimentin, the expression levels of HOXA10, LIF, CXCR4 proteins and CXCR4 mRNA in the BMSCs+EA+AMD3100 group were down-regulated (P<0.01). Results of H.E. staining showed thin endometrium with absence of epithelial cells, and sparse glands and blood vessels, with smaller glandular cavity in the model group, which was relative milder in BMSCs and BMSCs+EA groups. EA can promote the transfer of transplanted BMSCs to the damaged site through SDF-1/CXCR4 signaling related stem cell homing, thereby promoting thin endometrial regeneration, repairing endometrial injury, and improving endometrial tolerance in rats with thin endometrium.

Evaluation of the efficacy and safety of ultrasound guided injection of carbon nanoparticles as a preoperative localizing tool of non-palpable breast cancer and sentinel lymph nodes detection

Objective This study aimed to measure the efficacy of using carbon nanoparticles in the preoperative localization of early breast cancer (BC) cases as well as in the detection of sentinel lymph nodes in Egypt. In addition, the purpose of the study was to determine whether the efficacy of carbon nanoparticles outweighs their high price and additional shipping fees. Material and methods The current pilot study enrolled 16 early BC patients, particularly those eligible for breast-conserving surgery. All patients underwent standardized injection techniques. The operating surgeons provided comprehensive intraoperative findings and postoperative histopathological reports of the excised tissues. Results After neoadjuvant chemotherapy (NAC), downstaging of the study subjects was achieved until reaching the TNM stage of T1N1M0 and T1N0M0 in 2 cases (12.5%) and 14 cases (87.5%), respectively. Ultrasound-guided injection of carbon nanoparticles was done, followed by surgical excision on the same day or the day after injection. Eleven patients had positive mass lesions preoperatively, with a mean tumoral size of less than 1 cm in maximum dimension. Moreover, 6 out of the 11 patients showed positive black staining intraoperatively with an accuracy of 68.75%. Postoperative histopathological examination (the gold standard) of axillary specimens revealed that 3 out of 16 of the study population have positive tumor-infiltrated lymph nodes. However, only 2 of these cases demonstrated intra-operative black staining, with the black dye’s positive and negative predictive values of staining being 100% and 92.2%, respectively. Conclusions Preoperative carbon nanoparticle suspension injection is a safe and effective method for adequate tumoral localization in BC patients. Nevertheless, this pilot study did not provide strong evidence for the adequacy of sentinel lymph node detection due to the small sample size, high cost, and extra shipping fees of the carbon nanoparticles.

High glucose induces tau hyperphosphorylation in hippocampal neurons via inhibition of ALKBH5-mediated Dgkh m6A demethylation: a potential mechanism for diabetic cognitive dysfunction

Tau hyperphosphorylation in hippocampal neurons has an important pathogenetic role in the development of diabetic cognitive dysfunction. N6-methyladenosine (m6A) methylation is the most common modification of eukaryotic mRNA and is involved in regulating diverse biological processes. However, the role of m6A alteration in tau hyperphosphorylation of hippocampus neurons has not been reported. We found lower ALKBH5 expression in the hippocampus of diabetic rats and in HN-h cells with high-glucose intervention, accompanied by tau hyperphosphorylation. ALKBH5 overexpression significantly reversed tau hyperphosphorylation in high-glucose-stimulated HN-h cells. Furthermore, we found and confirmed by m6A–mRNA epitope transcriptome microarray and transcriptome RNA sequencing coupled with methylated RNA immunoprecipitation that ALKBH5 regulates the m6A modification of Dgkh mRNA. High glucose inhibited the demethylation modification of Dgkh by ALKBH5, resulting in decreases in Dgkh mRNA and protein levels. Overexpression of Dgkh reversed tau hyperphosphorylation in HN-h cells after high-glucose stimulation. Overexpression of Dgkh by adenovirus suspension injection into the bilateral hippocampus of diabetic rats significantly ameliorated tau hyperphosphorylation and diabetic cognitive dysfunction. In addition, ALKBH5 targeted Dgkh to activate PKC-α, leading to tau hyperphosphorylation under high-glucose conditions. The results of this study reveal that high glucose suppresses the demethylation modification of Dgkh by ALKBH5, which downregulates Dgkh and leads to tau hyperphosphorylation through activation of PKC-α in hippocampal neurons. These findings may indicate a new mechanism and a novel therapeutic target for diabetic cognitive dysfunction.

Study on naked eye tracing of inguinal sentinel lymph nodes in penile cancer patients with carbon nanoparticle suspension injection.

Exploratory study of the effect and clinical value of carbon nanoparticle suspension injection (CNSI) as a tracer for inguinal sentinel lymph nodes in penile cancer. We selected 29 patients with penile cancer in our department from January 2019 to October 2022. According to whether the CNSI tracer was injected during the pathological biopsy of the inguinal lymph nodes, the enrolled patients were assigned to the control group, the group in which CNSI was injected 12 h before the surgery (12HBS group) and the group in which CNSI was injected 0.5 h before the surgery (0.5HBS group). Evaluating the effectiveness of CNSI as a lymphatic tracer involves analyzing the following: its safety, the statistical analysis of the detection rate (DR) of different groups, the number of lymph nodes sent for each case (NOLNSFEC), the difference of positive rate of lymphatic metastasis (PROLM), and operation time (OT). The lymph nodes in the 12HBS group and 0.5HBS group had an obvious black staining appearance, and no adverse reactions or surgical complications were found. Most of the black-stained areas caused by CNSI injection were removed with penile excision, which did not affect the postoperative appearance. This did not affect the pathological analysis. The DR of lymph nodes in the 12HBS group was higher (p < 0.05) than that in the control group. More lymph nodes were removed for examination (p < 0.05), which improved the efficiency of surgery. Compared with the 12HBS group, the number of lymph nodes removed in the 0.5HBS group decreased (p < 0.05). The OT was shortened (p < 0.05), but there was no significant difference in the DR and PROLM. CNSI was applied to the naked-eye tracing of inguinal sentinel lymph nodes in penile cancer, which is safe and efficient. Injection of CNSI 0.5 h before surgery can help identify the "foremost position" of sentinel lymph nodes and reduce surgical trauma.

An NMR-assisted laboratory investigation of coal fines migration in fracture proppants during single-phase water production

Proppants are injected with the fracturing fluid to keep the hydraulic fractures open. However, deposition of coal fines in the void spaces between proppants significantly damage flow conductivity of the fractures. In this study, we experimentally model coal fines migration in a proppant pack. Standard quartz sand (16–20 mesh) is used to prepare the proppant pack. The proppant pack is installed within a low-field Nuclear Magnetic Resonance (NMR) facility to record NMR response before and after the experiment of fines suspension injection. The injected suspension consists of water with 500 ppm concentration of coal fines of radius from 2.8 to 142.9 µm. Coal fines are generated by crushing an anthracite coal sample. The permeability is damaged significantly by about 41% after 80 pore volume injection. NMR response suggests that volume of the large-size pores (radius rp > 60 um) decreases while that of the medium-size pores (0.9 um <rp < 60 um) increases. The pore structure change is caused by two possible mechanisms: (a) reducing pore size by fines occupying pore space and (b) developing inter-particulate pore space of fines gathering at the damaged pores. Although the fines size (radius from 2.8 to 142.9 um) is significantly smaller than the pore size (<1005.2 um), the large-size pores can still be damaged by the fines. The results of this study can help to understand mechanisms of fines migration and conductivity evolution in/of the hydraulic fractures during Coal Seam Gas production.

Discrete micro-volume suspension injection to microwave induced plasma for simultaneous determination of cadmium and lead pre-concentrated on multiwalled carbon nanotubes in optical emission spectrometry

A discrete sample introduction system (DSIS) for the direct micro-volume nanomaterials (NMs) suspension injection has been developed toward the simultaneous determination of Cd and Pb pre-concentrated (by dispersive micro solid-phase extraction (DMSPE)) on oxidized multiwalled carbon nanotubes (MWCNTs) to microwave induced plasma optical emission spectrometry (DMSPE-DSIS-MIP OES). On-axis low-volume spray chambers with flow focusing micro nebulizer (continues mode) and v-groove type pneumatic nebulizer (discontinues mode) for microliter-volume suspension introduction were tested.A univariate approach and the simplex optimization procedure were used to achieve optimized conditions and derive analytical figures of merit. Minimum dead volume, high nebulization and suspension transport efficiency were obtained by using miniaturized spray chamber/v-groove pneumatic nebulizer interface for 10 μL suspension injection in discontinues mode (at 0.5 mL min−1 pump speed).Analytical performance of DMSPE-DSIS-MIP OES method was characterized by determination of the limits of detection (0.7 and 0.1 ng mL−1 for Cd and Pb, respectively) and precision ranged from 6% to 8%. Quantitative data obtained for water reference materials (ERM-CA011b and SRM 1643e) were in good agreement, according to the t-test, for a confidence level of 95%, with the corresponding reference values, proving the potential of this analysis system for trace analysis via MIP OES. The proposed method had been successfully applied for the determination of Cd and Pb in water real samples.

The safety and efficacy of carbon nanoparticle suspension injection versus indocyanine green tracer-guided lymph node dissection during radical gastrectomy (FUTURE-01): A single-center randomized controlled trial protocol.

The use of lymph node (LN) tracers can help obtain a complete dissection of the lymph nodes and increase the detection rate of LNs and metastatic LNs. Carbon nanoparticle suspension injection (CNSI) and indocyanine green (ICG) have been widely used in radical gastrectomy in recent years. Nevertheless, the comparison of their clinical effects has not been studied. The FUTURE-01 trial will be the first randomized, open-label, single-center trial to compare CNSI and ICG. The study started in 2021 and enrolled 96 patients according to a prior sample size calculation. The primary outcome is the number of LNs retrieved. The secondary outcomes are LN staining rate, LN metastasis rate, stained LN metastasis rate, perioperative recovery and survival. By comparing the safety and efficacy of CNSI and ICG tracer-guided LN dissection in patients with gastric cancer, we can determine the most appropriate LN tracer at present. With the help of LN tracers, the operation is simplified, and the prognosis of these patients is improved. Our study is a prospective exploration of the safety, efficacy, and prognosis of CNSI and ICG. https://clinicaltrials.gov/ct2/show/NCT05229874?cond=NCT05229874&draw=2&rank=1, identifier NCT05229874.