Treatment with anti-programmed cell death protein 1 (PD-1) therapy and chemotherapy prolongs the survival of patients with unresectable advanced or metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma. The benefit from anti-PD-1 therapy is enriched in patients with programmed cell death 1 ligand 1 (PD-L1) combined positive score (CPS)-positive or CPS-high tumors compared with patients with PD-L1 CPS-negative or CPS-low tumors. In this phase 1b/2 study, we evaluated the efficacy and safety of cadonilimab, a bispecific antibody targeting PD-1 and cytotoxic T-lymphocyte antigen-4, plus chemotherapy as first-line treatment in patients with human epidermal growth factor receptor 2-negative unresectable advanced or metastatic gastric or GEJ adenocarcinoma. The primary endpoint was the recommended phase 2 dose (RP2D) for phase 1b and the objective response rate for phase 2. Secondary endpoints included disease control rate, duration of response, time to response, progression-free survival, overall survival (OS) and safety. The primary endpoint was met. No dose-limiting toxicities were observed during dose escalation in phase 1b; the recommended phase 2 dose was determined as 6 mg kg-1 every 2 weeks. The objective response rate was 52.1% (95% confidence interval (CI) = 41.6-62.5), consisting of complete and partial responses in 4.3% and 47.9% of patients, respectively. The median duration of response, progression-free survival and OS were 13.73 months (95% CI = 7.79-19.12), 8.18 months (95% CI = 6.67-10.48) and 17.48 months (95% CI = 12.35-26.55), respectively. The median OS in patients with a PD-L1 CPS ≥ 5 was 20.32 months (95% CI = 4.67-not estimable); in patients with a PD-L1 CPS < 1, the median OS reached 17.64 months (95% CI = 11.63-31.70). The most common treatment-related grade 3 or higher adverse events were decreased neutrophil count (19.1%), decreased platelet count (16.0%), anemia (12.8%) and decreased leukocyte count (8.5%). No new safety signal was identified. The current regimen showed promising clinical activity and manageable safety in patients with gastric or GEJ adenocarcinoma regardless of PD-L1 expression. Chinadrugtrials.org.cn registration: CTR20182027.
It is well known that DNA damage can cause apoptosis. However, whether apoptosis and its metabolites contribute to DNA repair is largely unknown. In this study, we found that apoptosis-deficient Fasmut and Bim- /- mice show significantly elevated DNA damage and premature cellular senescence, along with a significantly reduced number of 16,000 g apoptotic vesicles (apoVs). Intravenous infusion of mesenchymal stromal cell (MSC)-derived 16,000 g apoVs rescued the DNA damage and premature senescence in Fasmut and Bim-/- mice. Moreover, a sublethal dose of radiation exposure caused more severe DNA damage, reduced survival rate, and loss of body weight in Fasmut mice than in wild-type mice, which can be recovered by the infusion of MSC-apoVs. Mechanistically, we showed that apoptosis can assemble multiple nuclear DNA repair enzymes, such as the full-length PARP1, into 16,000 g apoVs. These DNA repair components are directly transferred by 16,000 g apoVs to recipient cells, leading to the rescue of DNA damage and elimination of senescent cells. Finally, we showed that embryonic stem cell-derived 16,000 g apoVs have superior DNA repair capacity due to containing a high level of nuclear DNA repair enzymes to rescue lethal dose-irradiated mice. This study uncovers a previously unknown role of 16,000 g apoVs in safeguarding tissues from DNA damage and demonstrates a strategy for using stem cell-derived apoVs to ameliorate irradiation-induced DNA damage.
Extracellular Vesicles , Animals , Mice , Cellular Senescence , DNA Damage , DNA Repair , DNA Repair Enzymes
Background: For patients who need laparoscopic radical gastrectomy, lymph node dissection (LND) and optimization of surgical procedures are particularly important. This study introduces the "quadrant-sandwich" method in clockwise modular D2 LND and evaluates the advantages and safety of this method. Methods: The clinical data of 108 laparoscopic total gastrectomy patients admitted to the Affiliated Cancer Hospital of Zhengzhou University from January 2019 to January 2022 were retrospectively analyzed. Based on the different LND processes, 55 patients were allocated to the observation group, which underwent clockwise modular LND using the "quadrant-sandwich method", and 53 patients were allocated to the control group, which underwent traditional LND. The effectiveness and safety of the approach in terms of operation time, blood loss, lymph node yield, postoperative recovery and postoperative complications were observed in the two groups. Results: There was no statistical difference between the baseline data of the two groups. In relation to the surgery, the observation group had an operation time of 227.0±48.5 minutes, and intraoperative bleeding of 100.0 mL [inter-quartile range (IQR), 30.0-200.0 mL], while the control group had an operation time of 247±41.5 minutes, and intraoperative bleeding of 180.0 mL (IQR, 130.0-245.0 mL). There were statistically significant differences between the two groups in terms of the operation time and intraoperative bleeding (P=0.001, P=0.020). In relation to the LND, there were no statistically significant differences between the two groups in terms of the total number of lymph nodes in each division, and the number of positive lymph nodes. In relation to the post-operative results, there were no statistically significant differences between the two groups in terms of the post-operative pathological stage, first postoperative oral feeding, post-operative hospitalization time, and post-operative complications. Conclusions: Clockwise modular D2 LND using the "quadrant-sandwich method" is potentially safe and feasible in laparoscopic total gastrectomy. It not only ensures the thoroughness of the LND, but also ensures and efficient and fast surgical process, shortens the operation time, and reduces the amount of intraoperative bleeding.
Background: At present, anastomotic fistula cannot be avoided after adenocarcinoma of the esophagogastric junction (AEG). Once the anastomotic leakage occurs, the posterior mediastinum and the left thoracic cavity are often seriously infected, which further impairs respiratory and circulatory function, heightening the danger of the disease course. The aim of this study was to identify the characteristics of superior anastomotic leakage after surgery for AEG and recommend corresponding treatment strategies to improve the diagnosis and treatment of superior anastomotic leakage after surgery for AEG. Methods: The clinical data of 57 patients with superior anastomotic leakage after surgery for AEG in the Affiliated Cancer Hospital of Zhengzhou University from January 2017 to March 2019 were retrospectively analyzed, including 27 cases referred from external hospitals and 30 cases at the Affiliated Cancer Hospital of Zhengzhou University. According to the diameter and risk level of anastomotic leakage, the high anastomotic leakage is divided into types I, II, III, and IV. Results: Patients with preoperative comorbidities or those treated with the transabdominal approach or laparoscopic surgery often had type I and type II anastomotic leakage; meanwhile, patients with preoperative comorbidities and sacral perforation or those treated with a thoracic and abdominal approach or open surgery often had type III and IV fistula. The difference between types I-II and types III-IV was statistically significant (P<0.05). The mortality rate of patients with type III and type IV leakage was 14.8% within 90 days after operation, while no deaths occurred among patients with type I and type II leakage, and the difference in mortality between the two groups was statistically significant (P<0.05). Conclusions: After surgery for AEG, suitable treatment measures should be adopted according to the type of superior anastomotic leakage that occurs. Types III and IV superior anastomotic leakages are associated with higher mortality and require greater attention from surgeons.
Background: Pelvic malignant tumors often originate in the rectum, bladder, uterus, and other organs. In patients with locally advanced tumours in the presence of direct invasion of one or more organs, negative tumor resection margin (R0) resection can be very beneficial to patient survival if it can be performed. As a multidisciplinary and high-risk surgical method, the pelvic exenteration (PE) procedure has only been reported in a few medical centres internationally. We retrospectively analyzed the clinical data of patients who had undergone PE surgery in our hospital, in order to provide ideas for the best treatment of patients with pelvic malignant tumors. Methods: A retrospective analysis was conducted of 59 patients with pelvic malignant tumors admitted to the Affiliated Cancer Hospital of Zhengzhou University from January 2015 to July 2021, all of whom received PE surgery. They were divided into two groups according to the location of the disease: the rectal cancer group (n=40) and the cervical cancer group (n=19). Statistical analysis was performed on the baseline and follow-up data of the two groups of patients. Results: (I) Patient baseline data. Compared to the rectal cancer group, more patients in the cervical cancer group received preoperative radiotherapy and chemotherapy (P=0.013), and had a lower R0 resection rate (P=0.037). Postoperative complications in patients with rectal cancer and cervical cancer were 27.5% and 47.3%, respectively. (II) Patient survival analysis after PE surgery. The 5-year survival rate was 36.6% in the rectal cancer group and 25.3% in the cervical cancer group. In the rectal cancer group, for the primary tumor, if there was no lymph node metastasis or no postoperative complications in the postoperative pathology, the patient had a good survival prognosis. Univariate analysis showed that recurrent rectal cancer, postoperative lymph node metastasis, postoperative complications, and microsatellite stability (MSS) were significant predictors of poor survival outcomes. Multivariate analysis showed that lymph node metastasis and postoperative complications were independent prognostic factors for patient survival. Conclusions: PE is a viable option for pelvic malignancies; aggressive radical resection of lesions and reduced postoperative complications can effectively improve patient outcomes.
Background: Microsatellite instability-high (MSI-H) is an important biomarker for predicting the effects of immune checkpoint inhibitors (ICIs) in colorectal cancer (CRC) patients. However, due to the low mutation rate of MSI-H/deficient mismatch repair (dMMR) in the overall population, some doctors are of the view that testing this indicator increases the burden on patients, and consequently some patients fail to receive the most beneficial treatment methods. In order to provide testing criteria for younger patients with a higher proportion of MSI-H, we designed this retrospective controlled study. Methods: A retrospective analysis was conducted of 1,901 patients who were admitted to the Affiliated Cancer Hospital of Zhengzhou University from January 2017 to December 2019 and underwent CRC-related gene testing. For this analysis, 100 patients aged 40 or younger are defined as the young group, and 305 patients aged 71 and older but younger than 80 are defined as the elderly group. We included patients who met the following criteria: (I) underwent preoperative colonoscopy or gastroscopy and were diagnosed with CRC; (II) received perioperative adjuvant therapy; (III) underwent curative surgery for CRC. Each patient was followed up from the time of surgery until April 30, 2023, or death, with follow-up visits scheduled every 3 months for the first 2 years after surgery, and every 6 months thereafter. Clinical characteristics such as age, gender, body mass index (BMI), tumor depth (T), number of metastatic lymph nodes (N), distant metastasis (M), tumor, node, metastasis (TNM) stage, extent of surgical resection, tumor size, tumor location, differentiation grade, and carcinoembryonic antigen (CEA) levels were collected. The microsatellite instability (MSI) status was analyzed using fluorescence in situ hybridization (FISH). Results: In young CRC patients, the proportion of MSI-H is higher than in elderly CRC patients (33% vs. 10.16%, P<0.001). The proportion of poorly differentiated tumors is also higher in young CRC patients compared to elderly CRC patients (53% vs. 31.15%, P<0.001). However, there were no significant differences in clinical characteristics between young and elderly CRC patients. In terms of prognosis, survival analysis of the young group showed that MSI status [hazard ratio (HR) =0.26, 95% confidence interval (CI): 0.08-0.88, P=0.03], TNM staging (HR =3.84, 95% CI: 1.38-10.71, P=0.010) were associated with the prognosis of CRC patients. Conclusions: The mutation rate of MSI-H is higher in young CRC patients compared to older. Our study further confirms that MSI-H can serve as a favorable prognostic marker for CRC patients. This finding may provide valuable guidance for clinicians in terms of prognosis assessment and treatment selection. If feasible, we hope that MSI testing can be performed for all CRC patients to enable targeted testing, with particular attention to monitoring the MSI status in young patients. This will aid clinicians in selecting appropriate treatment strategies for these patients.
Background: The first case of treatment with en bloc right hemicolectomy with pancreatoduodenectomy (RHCPD) for locally advanced right-sided colon cancer (LARCC) invading the pancreas, duodenum, or other organs, was reported in 1953 by Van Prohaska. Right-sided colon cancers invading the pancreas and duodenum are rare. Surgery can be technically challenging, with unclear oncologic consequences, hence there are few reports on the clinical outcomes and factors associated with survival in this patient cohort. The need for neoadjuvant chemotherapy in patients with LARCC is controversial, and the long-term survival of these patients as well as the preferred treatment regimen needs to be explored. This paper reports our experience in right hemicolectomy with en bloc resection for LARCC. We conducted this study to analyze the clinical features and surgical outcomes of LARCC. Methods: A retrospective study was performed using a database of all patients who underwent RHCPD due to the tumour directly invading the duodenum and/or pancreas in a 19-year period [2003-2022]. We included patients whose primary tumor site was the right hemicolon and who had undergone a negative tumor resection margin (R0) resection. In addition, the adhesions between the colon and other organs in these patients were malignant adhesions. The primary outcome was the overall survival after surgery. The secondary endpoints of the study included 30-day postoperative mortality, postoperative complications, prognostic factors, and tumour genetics. All patients were followed up with postoperative imaging at an interval of 3 months for the first 3 years and at an interval of 6 months for the next 2 years, and annual follow-up thereafter. Survival was estimated using Kaplan-Meier analysis. Variables with P values <0.05 in univariate analysis were entered into multivariate Cox proportional risk regression to identify independent predictors of survival. Results: There were 47 patients (23 males and 24 females) who underwent en bloc resection for LARCC. The median age of the patients was 61 years (range, 38-80 years). R0 resection was achieved in all cases. The overall complication rate was 27.7% (n=13). Two patients died within 30 days of surgery. The overall survival was 80.9%, 63.5%, and 51.7% at 1, 3, and 5 years, respectively. Univariate survival analysis identified pancreatic invasion, regional lymph node positivity, more than two organs invaded, and no neoadjuvant treatment as predictors of poor survival (log-rank P<0.05). Multivariate analysis showed that regional lymph node positivity [95% confidence interval (CI): 1.145-7.736; P=0.025] and more than two organs invaded (95% CI: 1.321-26.981; P=0.020) were predictors of poor survival. Conclusions: Relatively optimistic clinical outcomes from en bloc resection were demonstrated for patients with LARCC. For LARCC patients, en bloc resection can be carefully considered.
Neuronal neurofibrillary tangles containing Tau hyperphosphorylation proteins are a typical pathological marker of Alzheimer's disease (AD). The level of tangles in neurons correlates positively with severe dementia. However, how Tau induces cognitive dysfunction is still unknown, which leads to a lack of effective treatments for AD. Metal ions deposition occurs with tangles in AD brain autopsy. Reduced metal ion can improve the pathology of AD. To explore whether abnormally phosphorylated Tau causes metal ion deposition, we overexpressed human full-length Tau (hTau) in the hippocampal CA3 area of mice and primary cultured hippocampal neurons (CPHN) and found that Tau accumulation induced iron deposition and activated calcineurin (CaN), which dephosphorylates glycogen synthase kinase 3 beta (GSK3ß), mediating Tau hyperphosphorylation. Simultaneous activation of CaN dephosphorylates cyclic-AMP response binding protein (CREB), leading to synaptic deficits and memory impairment, as shown in our previous study; this seems to be a vicious cycle exacerbating tauopathy. In the current study, we developed a new metal ion chelator that displayed a significant inhibitory effect on Tau phosphorylation and memory impairment by chelating iron ions in vivo and in vitro. These findings provide new insight into the mechanism of memory impairment induced by Tau accumulation and develop a novel potential treatment for tauopathy in AD.
Alzheimer Disease , Tauopathies , Humans , Animals , Mice , Mice, Transgenic , Alzheimer Disease/metabolism , tau Proteins/metabolism , Tauopathies/pathology , Memory Disorders/drug therapy , Memory Disorders/etiology , Chelating Agents/pharmacology , Chelating Agents/therapeutic use , Ions , Iron , Phosphorylation , Glycogen Synthase Kinase 3 beta/metabolism
In this paper, a specific type of Boron Carbide (B4C) with a high enrichment of 80 ± 0.3 at% 10B was prepared as an absorbing material for control rods in nuclear reactors. The enrichment of 10B was achieved using a chemical exchange method, followed by obtaining boron carbide powder through a carbothermal reduction method. Finally, B4C with a high enrichment of 68.3~74.2% theoretical density was obtained using a hot-pressed sintering process. This study focused on investigating the basic out-of-pile thermophysical properties of the high enrichment B4C compared to natural B4C reference pellets under non-irradiated conditions. These properties included the thermal expansion coefficient, thermal conductivity, emissivity, elastic limit, elastic modulus, and Poisson's ratio. The research results indicate that the enriched B4C pellet exhibits good thermal stability and meets the technical requirements for mechanical capability. It was observed that porosity plays a significant role in determining the out-of-pile mechanical capability of B4C, with higher porosity samples having a lower thermal conductivity, elastic-plastic limit, and elastic modulus. In short, all the technical indexes studied meet the requirements of nuclear-grade Boron Carbide pellets for Pressurized Water Reactors.
[This corrects the article DOI: 10.3389/fcell.2021.734287.].
Melanoma cells were more resistant to ferroptosis with still poor therapy outcomes. Sensitizing melanoma cell to the ferroptosis inducer was a crucial strategy for treatment of melanoma. In the present study, 2,2'-di-pyridylketone hydrazone dithiocarbamate s-butyric acid (DpdtbA) displayed superior inhibitory activity than ferroptosis inducer Erastin in melanoma cells, which prompt us to explore the underlying mechanism. The analyses from flow cytometry and Western blot showed that the growth inhibition of DpdtbA against SK-MEL-28 and A375 cells involved apoptosis induction and G1 phase arrest. Surprisingly, the cytoplasmic vacuoles were found upon the treatment; transmission electron microscopy and endoplasmic reticulum (ER) staining revealed that the cytoplasmic vacuoles were in ER; while down-regulation of alix and requirement of protein synthesis suggested there was an occurrence of paraptosis. However, both NAC and 3-MA could significantly attenuate the cytoplasmic vacuolization and growth inhibition, hinting that both ROS and autophagy involved the paraptosis induction. The additional evidence revealed that there was an occurrence of continuous ferritinophagy, which was responsible for the ROS production. Downregulation of NCOA4 clearly attenuated the apoptosis and paraptosis induction. In addition, activation of MAPK involved regulation of paraptosis, but only ERK and JNK had role in the formation of cytoplasmic vacuoles and growth inhibition. Furthermore, a ROS dependent regulation of PI3K/AKT pathway was also involved. Taken together, our result firstly demonstrated that a continuous ferritinophagy contributed to the apoptosis and paraptosis induction, highlighting that the lysosomal labile iron pool had a crucial role in control of melanoma cell fate.
Melanoma , Proto-Oncogene Proteins c-akt , Humans , Proto-Oncogene Proteins c-akt/metabolism , Phosphatidylinositol 3-Kinases , Reactive Oxygen Species/metabolism , Apoptosis , Iron Chelating Agents/pharmacology , Autophagy , Cell Line, Tumor
BACKGROUND: Immune checkpoint inhibitors targeting PD-1 or CTLA-4 individually have shown substantial clinical benefits in the treatment of malignancies. We aimed to assess the safety and antitumour activity of cadonilimab monotherapy, a bispecific PD-1/CTLA-4 antibody, in patients with advanced solid tumours. METHODS: This multicentre, open-label, phase 1b/2 trial was conducted across 30 hospitals in China. Patients aged 18 years or older with histologically or cytologically confirmed, unresectable advanced solid tumours, unsuccessful completion of at least one previous systemic therapy, and an Eastern Cooperative Oncology Group performance status of 0 or 1 were eligible for inclusion. Patients who had previously received anti-PD-1, anti-PD-L1, or anti-CTLA-4 treatment were not eligible for inclusion. In the dose escalation phase of phase 1b, patients received intravenous cadonilimab at 6 mg/kg and 10 mg/kg every 2 weeks. In the dose expansion phase of phase 1b, cadonilimab at 6 mg/kg and a fixed dose of 450âmg were given intravenously every 2 weeks. In phase 2, cadonilimab at 6 mg/kg was administered intravenously every 2 weeks in three cohorts: patients with cervical cancer, oesophageal squamous cell carcinoma, and hepatocellular carcinoma. The primary endpoints were the safety of cadonilimab in phase 1b and objective response rate in phase 2, based on the Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1. The safety analysis was done in all patients who received at least one dose of cadonilimab. Antitumour activity was assessed in the full analysis set for the cervical cancer cohort, and in all patients with measurable disease at baseline and who received at least one dose of cadonilimab in the oesophageal squamous cell carcinoma and hepatocellular carcinoma cohorts. The study is registered on ClinicalTrial.gov, NCT03852251, and closed to new participants; follow-up has been completed. FINDINGS: Between Jan 18, 2019, and Jan 8, 2021, 240 patients (83 [43 male and 40 female] in phase 1b and 157 in phase 2) were enrolled. Phase 2 enrolled 111 female patients with cervical cancer, 22 patients with oesophageal squamous cell carcinoma (15 male and seven female), and 24 patients with hepatocellular carcinoma (17 male and seven female). During dose escalation, no dose-limiting toxicities occurred. Grade 3-4 treatment-related adverse events occurred in 67 (28%) of 240 patients; the most frequent grade 3 or worse treatment-related adverse events were anaemia (seven [3%]), increased lipase (four [2%]), decreased bodyweight (three [1%]), decreased appetite (four [2%]), decreased neutrophil count (three [1%]), and infusion-related reaction (two [1%]). 17 (7%) patients discontinued treatment due to treatment-related adverse events. 54 (23%) of 240 patients reported serious treatment-related adverse events, including five patients who died (one due to myocardial infarction; cause unknown for four). In phase 2, in the cervical cancer cohort, with a median follow-up of 14·6 months (IQR 13·1-17·5), the objective response rate was 32·3% (32 of 99; 95% CI 23·3-42·5). In the oesophageal squamous cell carcinoma cohort, with a median follow-up of 17·9 months (IQR 4·0-15·1), the objective response rate was 18·2% (four of 22; 95% CI 5·2-40·3). In the hepatocellular carcinoma cohort, with a median follow-up of 19·6 months (IQR 8·7-19·8), the objective response rate was 16·7% (four of 24; 95% CI 4·7-37·4). INTERPRETATION: Cadonilimab showed an encouraging tumour response rate, with a manageable safety profile, suggesting the potential of cadonilimab for the treatment of advanced solid tumours. FUNDING: Akeso Biopharma. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.
Antineoplastic Agents, Immunological , Carcinoma, Hepatocellular , Esophageal Neoplasms , Esophageal Squamous Cell Carcinoma , Liver Neoplasms , Uterine Cervical Neoplasms , Humans , Male , Female , Carcinoma, Hepatocellular/drug therapy , Esophageal Squamous Cell Carcinoma/drug therapy , Uterine Cervical Neoplasms/drug therapy , CTLA-4 Antigen , Programmed Cell Death 1 Receptor , Empathy , Antibodies, Monoclonal, Humanized , Antineoplastic Agents, Immunological/adverse effects , Esophageal Neoplasms/drug therapy , Esophageal Neoplasms/chemically induced , Liver Neoplasms/drug therapy , Antineoplastic Combined Chemotherapy Protocols/therapeutic use
Hematopoietic stem cells (HSCs) sustain hematopoiesis during homeostasis and regeneration. However, their limited availability poses a challenge for protein analysis. Here, we present a protocol for performing high-sensitivity western blot on HSCs using two techniques that enhance HSC isolation from mice and boost sensitivity for low cell numbers. We describe steps for isolating murine bone marrow cells, antibody staining, and cell sorting and post-sort analysis. We then detail a western blot procedure suitable for low numbers of HSCs. For complete details on the use and execution of this protocol, please refer to Li et al (2022).1,2.
Hematopoiesis , Hematopoietic Stem Cells , Animals , Mice , Hematopoietic Stem Cells/metabolism , Cell Separation , Bone Marrow Cells , Blotting, Western
Nowadays, there have been extensively theoretical studies on the phenomenon of ion current rectification (ICR) induced by the asymmetric electrical double layer (EDL). As a key factor influencing the behavior of ion transport, temperature is given high priority by researchers. The thermal conductivity of the material commonly employed to prepare nanopores is 2-3 times higher than that of liquid solutions, which may affect ion transport within the nanochannel. However, it is often neglected in previous studies. Thus, we investigate the effect of membrane thermal conductivity on the ICR in conical nanochannels under asymmetric temperature. Based on the PNP-NS theoretical model, the ion current, the rectification ratio, as well as the temperature and ion concentration distributions along the nanochannel are calculated. It is found that the thermal conductivity of the solid membrane noticeably affects the temperature distribution across the nanochannel, altering the ion transport behavior. Larger membrane thermal conductivity tends to homogenize the temperature distribution in the nanochannel, leading to a decline of ionic thermal down-diffusion by a positive temperature difference and ionic thermal up-diffusion by a negative temperature difference, with the former promoting and the latter inhibiting ion current. As a result, the rectification ratio decreases under the positive temperature difference and increases under the negative temperature difference as the thermal conductivity of the membrane increases. These studies will be instructive for the design of nanofluidic diodes and biosensors.
Tau protein hyperphosphorylation and formation of intracellular neurofibrillary tangles (NFTs) are one of the histopathological hallmarks of Alzheimer's disease (AD) and positively correlated with the severity of AD symptoms. NFTs contain a large number of metal ions that play an important role in regulating tau protein phosphorylation and AD progression. Extracellular tau induces primary phagocytosis of stressed neurons and neuronal loss by activating microglia. Here, we studied the effects of a multi-metal ion chelator, DpdtpA, on tau-induced microglial activation and inflammatory responses and the underlying mechanisms. Treatment with DpdtpA attenuated the increase in the expression of NF-κB and production of inflammatory cytokines, IL-1ß, IL-6 and IL-10, in rat microglial cells induced by expression of human tau40 proteins. Treatment with DpdtpA also suppressed tau protein expression and phosphorylation. Moreover, treatment with DpdtpA prevented tau-induced activation of glycogen synthase kinase-3ß (GSK-3ß) and inhibition of phosphatidylinositol-3-hydroxy kinase (PI3K)/AKT. Collectively, these results show that DpdtpA can attenuate tau phosphorylation and inflammatory responses of microglia by regulating the PI3K/AKT/GSK-3ß signal pathways, providing a new option to alleviate neuroinflammation for the treatment of AD.
Alzheimer Disease , tau Proteins , Rats , Humans , Animals , tau Proteins/metabolism , Phosphatidylinositol 3-Kinase/metabolism , Phosphatidylinositol 3-Kinase/pharmacology , Phosphorylation , Microglia/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Glycogen Synthase Kinase 3 beta/metabolism , Signal Transduction , Alzheimer Disease/metabolism , Chelating Agents/pharmacology
Artificial bionic nanochannels have attracted wide attention and successfully used in various fields. In this work, a novel nanochannel with asymmetric surface charge is proposed to investigate the ion enrichment effect. The results show that the proposed nanochannel has excellent ion enrichment performance and the obtained ion enrichment ratio is up to 1500 when the ion concentration is 0.01 mM, which is much higher than precedent researches typically ranging from tens to hundreds. Besides, we found that the forward voltage bias will produce ions enrichment and the reverse voltage bias will produce ions depletion. The ion enrichment ratio is higher at the larger voltage bias, absolute surface charge density and smaller nanochannel height. In addition, the ion enrichment performance is more sensitive to the change of charged wall length and not sensitive to the change of uncharged wall length. The research report offers important information and instructions for the design and optimum on ion enrichment performance.
Micro/nano electronic devices heat dissipation depends heavily on the thermal interface materials (TIMs). Despite notable progress, it is hard to efficaciously enhance the thermal properties of the hybrid TIMs with high-load additives due to an absence of effective heat transfer routes. Herein, the low content of three-dimensional (3D) graphene with interconnected networks is adopted as the additive to improve the thermal properties of epoxy composite TIMs. The thermal diffusivity and thermal conductivity of the as-prepared hybrids were dramatically improved by constructing thermal conduction networks after adding 3D graphene as fillers. The 3D graphene/epoxy hybrid's optimal thermal characteristics were observed at 1.5 wt% of 3D graphene content, corresponding to a maximum enhancement of 683%. Besides, heat transfer experiments were further performed to determine the superb heat dissipation potential of the 3D graphene/epoxy hybrids. Moreover, the 3D graphene/epoxy composite TIM was also applied to high-power LED to improve heat dissipation. It effectively reduced the maximum temperature from 79.8 °C to 74.3 °C. These results are beneficial for the better cooling performance of electronic devices and provide useful guidelines for advancing the next-generation TIMs.
