Organic-Inorganic Hybrid Cuprous-Based Metal Halides with Unique Two-Dimensional Crystal Structure for White Light-Emitting Diodes.

Ternary cuprous (Cu+)-based metal halides, represented by cesium copper iodide (e.g., CsCu2I3 and Cs3Cu2I5), are garnering increasing interest for light-emitting applications owing to their intrinsically high photoluminescence quantum yield and direct bandgap. Toward electrically driven light-emitting diodes (LEDs), it is highly desirable for the light emitters to have a high structural dimensionality as it may favor efficient electrical injection. However, unlike lead-based halide perovskites whose light-emitting units can be facilely arranged in three-dimensional (3D) ways, to date, nearly all ternary Cu+-based metal halides crystallize into 0D or 1D networks of Cu-X (X = Cl, Br, I) polyhedra, whereas 3D and even 2D structures remain mostly uncharted. Here, by employing a fluorinated organic cation, we report a new kind of ternary Cu+-based metal halides, (DFPD)CuX2 (DFPD+ = 4,4-difluoropiperidinium), which exhibits unique 2D layered crystal structure. Theoretical calculations reveal a highly dispersive conduction band of (DFPD)CuBr2, which is beneficial for charge carrier injection. It is also of particular significance to find that the 2D (DFPD)CuBr2 crystals show appealing properties, including improved ambient stability and an efficient warm white-light emission, making it a promising candidate for single-component lighting and display applications.

Boosting Type-I and Type-II ROS Production of Water-Soluble Porphyrin for Efficient Hypoxic Tumor Therapy.

As the most successful clinically approved photosensitizers, porphyrins have been extensively employed in the photodynamic therapy (PDT) of cancers. However, their poor water solubility, aggregation-induced self-quenching on ROS generation, and a low tolerance for a hypoxic condition usually result in unsatisfied therapeutic outcomes. Therefore, great efforts have been dedicated to improving the PDT efficacy of porphyrin-type photosensitizers in treating hypoxic tumors, including combination with additional active components or therapies, which can significantly complicate the therapeutic process. Herein, we report a novel water-soluble porphyrin with O-linked cationic side chains, which exhibits good water solubility, high photostability, and significantly enhanced ROS generation efficacy in both type-I and type-II photodynamic pathways. We have also found that the end charges of side chains can dramatically affect the ROS generation of the porphyrin. The cationic porphyrin exhibited high in vitro PDT efficacy with low IC50 values both in normoxia and hypoxia. Hence, during in vivo PDT study, the cationic porphyrin displayed highly effective tumor ablation capability. This study demonstrates the power of side-chain chemistry in tuning the photodynamic property of porphyrin, which offers a new effective strategy to enhance the anticancer performance of photosensitizers for fulfilling the increasing demands for cancer therapy in clinics.

A Risk Prediction Model for Post-endoscopic Retrograde Cholangiopancreatography Pancreatitis After Stent Insertion for Malignant Biliary Obstruction: Development and Validation.

OBJECTIVES: Pancreatitis is the most common complication of post-endoscopic retrograde cholangiopancreatography (ERCP). There are currently no prediction models, particularly for post-ERCP pancreatitis (PEP) after biliary stent placement due to malignant biliary obstruction (MBO). To that end, we aim to develop and validate a predictive model for PEP. METHODS: We retrospectively analyzed the data of patients who underwent ERCP for biliary stent placement due to MBO at the Second Affiliated Hospital of Harbin Medical University from January 1, 2014 to August 31, 2021. The eligible patients were randomly allocated to the development and validation cohorts. A prediction model was built using the development cohort, and the model's effect was validated using a validation cohort. RESULTS: A total of 1524 patients were enrolled, including 1016 in the development cohort and 508 in the validation cohort, with an overall PEP rate of 7.1%. The model's predictors included acute pancreatitis history, the absence of pancreatic duct dilation, nonpancreatic cancer, difficult cannulation, and pancreatic injection. The area under the curve (AUC) in the development cohort was 0.810, and the incidence of PEP in the low-risk, medium-risk, and high-risk groups was 1.53%, 9.12%, and 36.36%, respectively. Meanwhile, the AUC of the validation cohort was 0.781, and the incidence of PEP in the low-risk, medium-risk, and high-risk groups was 4.17%, 8.75%, and 41.67%, respectively. CONCLUSIONS: This study was the first to build and validate a risk prediction model, especially for PEP after biliary stent placement due to MBO. Moreover, this model might assist clinicians in identifying high-risk patients and help implement preventive measures in a more timely manner.

Synthesis of Noble Metal M@YSiO2 Yolk-Shell Nanoparticles with Thin Organic/Inorganic Hybrid Outer Shells via an Aqueous Medium Phase.

A simple method is proposed for the synthesis of noble metal M@YSiO2 (M = Au, Pd, Ag) yolk-shell nanoparticles. The effects of synthesis conditions on the preparation of yolk-shell nanoparticles were discussed in detail. According to the different corrosion resistances between inorganic silica and organosilicone in a selective etching solution, yolk-shell nanoparticles with large cavity and thin shell were prepared using the same aqueous medium in a step-by-step synthesis process. Different from traditional methods, this method is facile and efficient because the main synthesis process is carried out in an aqueous phase. This extended method may benefit the synthesis and application of other nanomaterials with a similar yolk-shell structure.

Individualized endoscopic management strategy for impacting jujube pits in the upper gastrointestinal tract: a 3-year single-center experience in northern China.

BACKGROUND: Impaction of jujube pits in the upper gastrointestinal (GI) tract is a special clinical condition in the northern Chinese population. Endoscopic removal is the preferred therapy, but there is no consensus on the management strategies. We reported our individualized endoscopic strategies on the jujube pits impacted in the upper GI tract. METHODS: In this retrospective study, we included 191 patients (male: 57; female: 134) who presented to our hospital with ingestion of jujube pits between January 2015 and December 2017. Demographic information, times of hospital visiting, locations of jujube pits, endoscopic procedures, post-extraction endoscopic characteristics were analyzed. Management strategies including sufficient suction, repeated irrigation, jejunal nutrition and gastrointestinal decompression were given based on post-extraction endoscopic characteristics and impacted locations. RESULTS: Peak incidence was in the second quarter of each year (85/191 cases, 44.5%). Among the 191 cases, 169 (88.5%) showed pits impaction in the esophagus, 20 (10.5%) in the prepyloric region and 2 (1.0%) in the duodenal bulb. A total of 185 patients (96.9%) had pits removed with alligator jaw forceps, and 6 (3.1%) underwent suction removal with transparent caps placed over the end of the endoscope to prevent injury on removal of these pits with two sharp painted edges. Post-extraction endoscopic manifestations included mucosal erosion (26.7%), mucosa laceration (24.6%), ulceration with a white coating (18.9%) and penetrating trauma with pus cavity formation (29.8%). All patients received individualized endoscopic and subsequent management strategies and showed good outcomes. CONCLUSIONS: Individualized endoscopic management for impacted jujube pits in the upper GI tract based on post-extraction endoscopic characteristics and impacted locations was safe, effective, and minimally invasive.

Esophageal insufflation computed tomography for the diagnosis and management of esophageal submucosal tumors.

BACKGROUND: The selection of therapy for benign esophageal lesions depends in part on whether the lesion extends to or through the esophageal muscle wall. The advent of endoscopic dissection of deep lesions has made this distinction important in the choice between different forms of advanced endoscopic therapy. The goal of this study was to evaluate esophageal insufflation computed tomography (EICT) for the diagnosis and management of esophageal submucosal tumors (SMTs). METHODS: Between April 2011 and May 2013 at the Second Affiliated Hospital of Harbin Medical University, 27 patients with esophageal SMTs diagnosed by gastroscopy were studied observationally. Entry criteria included tumors larger than 0.5 cm. We compared endoscopic ultrasound (EUS) and EICT to assess lesion depth and the relationship between the submucosal lesion and the esophageal wall using the resected lesion as the gold standard. RESULTS: Twenty-seven esophageal SMTs were evaluated. EUS and EICT accurately identified nine as superficial to the muscularis propria. EICT correctly identified the relation of the tumor extension and the outer esophageal wall in all 18 lesions that originated from the muscularis propria; only nine were correctly assessed by EUS (P < 0.001). CONCLUSIONS: EICT enables improved judgment of the relation of esophageal lesions and the esophageal-mediastinal border. We propose EICT as a new, safe, effective, useful, simple and high-tolerance method for assessing the depth and relationships of esophageal submucosal lesions.

An engineered coiled-coil polypeptide assembled onto quantum dots for targeted cell imaging.

Quantum dot (QD)-polypeptide probes have been developed through the specific metal-affinity interaction between polypeptides appended with N-terminal polyhistidine sequences and CdSe/ZnS core-shell QDs. The size and charge of a QD-polypeptide can be tuned by using different coiled-coil polypeptides. Compared to glutathione-capped QDs (QD-GSH), QD-polypeptide probes showed an approximately two- to three-fold luminescence increase, and the luminescence increase was not obviously related to the charge of the polypeptide. QD-polypeptide probes with different charge have a great effect on nonspecific cellular uptake. QD-polypeptide probes with negative charge exhibited lower nonspecific cellular uptake in comparison to the QD-GSH, while positively charged QD-polypeptide probes presented higher cellular uptake than the QD-GSH. A targeted QD-ARGD probe can obviously increase targeted cellular uptake in α v ß 3 overexpressing HeLa cells compared to QD-A. In addition, QD-polypeptide probes showed lower in vitro cytotoxicity compared to the original QDs. These results demonstrate that these QD-polypeptide probes with high specific cellular uptake, high fluorescence intensity and low background noise are expected to have great potential applications in targeted cell imaging.

Dual-Responsive hollow mesoporous organosilicon nanocarriers for photodynamic therapy.

HYPOTHESIS: The nano-delivery platform, -SS-HMONs@MB@MnO2 nanoparticles (SMM NPs) loaded with methylene blue (MB) as photosensitizer have excellent photodynamic therapy (PDT) effect. The disulfide bond and MnO2 give the shell redox-responsive properties. SMM NPs consume glutathione (GSH) in tumor cells, reducing the scavenging of reactive oxygen species (ROS) by GSH and enhancing the PDT effect of MB. EXPERIMENTS: The GSH dual-responsive nano-delivery platform, was designed and constructed by using disulfide-doped hollow mesoporous organosilicon nanoparticles (-SS-HMONs) as intermediate responsive layer, loaded with MB as photosensitizer and coated with MnO2 as shells. The MB photosensitizer release and GSH response were characterized. The PDT effect of nanoparticles was evaluated. FINDINGS: The SMM NPs were uniform in size and well dispersed. The nanoparticles could react with GSH, leading to the decomposition of MnO2 shells and the breakage of disulfide bonds in -SS-HMONs, resulted in the release of MB photosensitizer. The cell experiment showed that SMM NPs had good ROS generating ability and PDT effect after being sucked by tumor cells, which could effectively kill tumor cells. However, in vivo experiments demonstrated that SMM NPs showed slight inhibition on tumor growth. The actual effect in animals was different from the effect in cells.

Tunneling endoscopic muscularis dissection for subepithelial tumors originating from the muscularis propria of the esophagus and gastric cardia.

BACKGROUND AND AIMS: Endoscopic resection of esophageal or cardial subepithelial tumors (SETs) originating from the muscularis propria (MP) is rarely done due to the high risk of perforation, fistula formation, and secondary infection. The aim of this study was to evaluate the preliminary clinical feasibility and safety of tunneling endoscopic muscularis dissection (tEMD) for resection of SETs located in the esophagus and gastric cardia METHODS: Twelve patients with SETs originating from the MP of the esophagus (n = 7) or cardia (n = 5) were treated by tEMD. The procedure included creation of a submucosal tunnel to reach the tumor, dissection of the tumor from the surrounding submucosal tissue and the unaffected MP layer, full-thickness resection of the tumor and affected MP, and subsequent closure of the tunnel mucosal entry with endoscopic clips. RESULTS: The en bloc resection rate was 100 % (seven lesions affected the deep MP so complete MP resection was performed; five lesions affected the superficial MP for a partial MP resection). The average tumor size was 18.5 ± 6.9 (range 10-30) mm. The mean operating time was 78.3 ± 25.5 (range 50-130) min. The histological diagnoses were two gastrointestinal stromal tumors with very low risk, nine leiomyomas, and one schwannoma. Air leakage and effusion included subcutaneous and mediastinal emphysema in eight patients (66.7 %), pneumothorax in four (33.3 %), pneumoperitoneum in three (25.0 %), and small pleural effusion in two (16.7 %). All air leakage and effusion cases were resolved with conservative management. No patient developed delayed hemorrhage and chronic fistula after tEMD. During the mean follow-up time of 7.1 ± 4.3 (range 2-15) months, no tumor recurrence was found in any patient. CONCLUSIONS: tEMD appears to be a feasible minimally invasive and effective treatment for patients with SETs originating from the MP layer of the esophagus and cardia.

Antimicrobial protection of two controlled release silver nanoparticles on simulated silk cultural relic.

HYPOTHESIS: Silver nanoparticles coated with organic-inorganic hybrid silica or inorganic silica have antimicrobial ability, and the coating can also effectively improve the dispersion and stability of the particles. The slow release of silver ions (Ag+) can improve the antimicrobial activity of silver nanoparticles. The synthesized nanoparticles are light yellow, which does not affect the look and feel of the silk cultural relics and meets the requirements of the principle of minimum interference. EXPERIMENTS: Two kinds of silver-based nanoparticles were synthesized: silver core-shell nanoparticle (Ag@mSiO2) and silver yolk-shell nanoparticle (Ag@YSiO2). The morphology, surface properties and Ag+ release efficiency of two nanoparticles were characterized. The antimicrobial effects of two nanoparticles on Aspergillus niger (A. niger) and Penicillium citrinum (P. citrinum) were compared. FINDINGS: Both of Ag@mSiO2 and Ag@YSiO2 had uniform size and good stability. Two nanoparticles had pore structure and silver nanocore, which provided the basis for the dissolution and exchange of Ag+. Because more silver ions were released, Ag@mSiO2 had higher antimicrobial activity than Ag@YSiO2 for A. niger and P. citrinum. For various silk samples, Ag@mSiO2 exhibited excellent antimicrobial properties. Meanwhile, there was little change in the color and tearing strength of Ag@mSiO2 coated silk.

Integration of Activation by Hypoxia and Inhibition Resistance of Tumor Cells to Apoptosis for Precise and Augmented Photodynamic Therapy.

Photodynamic therapy (PDT) uses photosensitizers to convert oxygen (O2 ) to reactive oxygen species (ROS) under irradiation to induce DNA damage and kill cancer cells. However, the effect of PDT is usually alleviated by apoptosis resistance mechanism of tumor living cells. MTH1 enzyme is known to be such an apoptosis-resistance enzyme which is over expressed as a scavenger to repair the damaged DNA. In this work, a hypoxia-activated nanosystem FTPA, which can be degraded to release the encapsulated PDT photosensitizer 4-DCF-MPYM and an inhibitor TH588 is proposed. The inhibitor TH588 can inhibit the DNA repair process by reducing the activity of MTH1 enzyme, and achieve the purpose of amplifying the therapeutic effect of PDT. This work demonstrates that a precise and augmented tumor PDT is achieved by integration of hypoxia-activation and inhibition resistance of tumor cells to apoptosis.

Endoscopic retrograde appendicitis therapy: a pilot minimally invasive technique (with videos).

BACKGROUND: Inspired by the success of ERCP for the treatment of suppurative cholangitis, we investigated a new minimally invasive method for the treatment of acute uncomplicated appendicitis, which we call endoscopic retrograde appendicitis therapy. OBJECTIVE: To investigate the feasibility and efficacy of endoscopic retrograde appendicitis therapy for the treatment of acute uncomplicated appendicitis. DESIGN AND SETTING: A retrospective, single-center study at an academic medical center. PATIENTS: Four patients with acute uncomplicated appendicitis. INTERVENTIONS: There were 5 steps after insertion of a colonoscope into the cecum and identification of the appendiceal orifice: (1) endoscopic appendiceal intubation; (2) appendiceal decompression; (3) retrograde appendicography; (4) stent drainage; and (5) cleansing the appendiceal lumen. MAIN OUTCOME MEASUREMENTS: The rate of successful endoscopic intubation and decompression, the time to symptom relief, the time to disappearance of signs, increased white blood cell count, procedure-related complications, and recurrence, if any. RESULTS: All 4 endoscopic appendiceal intubations were successful. Pain was relieved immediately after endoscopic decompression and stent drainage. Leukocytosis returned to normal within 24 hours. There were no complications and no recurrences during 4 to 19 months of follow-up. LIMITATIONS: Small sample size, single-center study without controls. CONCLUSION: Endoscopic retrograde appendicitis therapy is a feasible and effective endoscopic treatment modality for acute uncomplicated appendicitis.

Endoscopic muscularis dissection for upper gastrointestinal subepithelial tumors originating from the muscularis propria.

BACKGROUND AND AIMS: Based on our experience with endoscopic submucosal dissection (ESD) and new endoscopic techniques for endoscopic closure of iatrogenic upper gastrointestinal (upper-GI) perforations, we developed methods to remove upper-GI subepithelial tumors (SETs) originating from the muscularis propria by endoscopic muscularis dissection (EMD). The aim of this study is to evaluate the clinical feasibility and safety of EMD. METHODS: 31 patients with upper-GI SETs originating from the muscularis propria were treated by EMD. The EMD differed from ESD in (1) precutting the overlying mucosa above the lesion by using snare or longitudinal incision instead of circumferential incision, (2) dissecting the complete tumors away from submucosal and muscularis propria tissue by electrical dissection combined with blunt dissection, and (3) closing the wound with clips. Perforations occurring during dissection were closed by endoscopic methods. RESULTS: 30 of 31 tumors were resected completely (96.8 %). One esophageal lesion was resected partially because of severe adhesions with surrounding tissue. Mean resected tumor size was 22.1 mm × 15.5 mm, and mean operation time was 76.8 min (range 15-330 min). Histological diagnosis was gastrointestinal stromal tumor (GIST) in 16 lesions [6 esophageal, 3 cardial, 7 gastric; 6 very low risk and 10 low risk according to the National Institutes of Health (NIH) risk classification] and leiomyoma in 15 lesions (8 esophageal, 4 cardial, 3 gastric). No patient developed delayed hemorrhage. Perforation occurred in four patients (12.9 %), all of which were managed successfully by endoscopic techniques. The mean follow-up time was 17.7 months (range 7-35 months). Follow-up found no tumor recurrence in any patient. CONCLUSIONS: In this early experience, EMD appears to be a feasible and minimally invasive treatment for some patients with upper-GI SETs originating from the muscularis propria. Although there is a higher risk of perforation than with ESD, this will improve with extended practice, and perforations have become manageable endoscopically.

Bioinformatics analysis of the prognostic and immunotherapeutic significance of NPRL2 in stomach adenocarcinoma.

Background: Stomach adenocarcinoma (STAD) is a major type of gastric cancer with high morbidity and mortality. NPRL2, a candidate cancer suppressor gene, has been shown to have anti-cancer effects in various types of cancers. Therefore, comprehensive analyses of NPRL2 in STAD may provide a potential prognostic marker and clinical target for the management of gastric cancer. Methods: Genomic expression and methylation were analysed based on data from the Human Protein Atlas, Gene Expression Omnibus and Oncomine database. Survival analyses were conducted with the Kaplan-Meier method, using data from The Cancer Genome Atlas database. Immune correlation analyses and prediction of response to immunotherapy were performed using the online Immune Cell Abundance Identifier. Co-expression analyses, functional clustering analyses and construction of a prognostic risk model were conducted in R, with the clinical covariates balanced by the inverse probability treatment weighting method. Results: NPRL2 was abnormally downregulated in STAD (P<0.05). Survival analysis highlighted a positive association between the expression of NPRL2 and clinical outcomes for patients (P<0.05). Based on co-expression analyses, we found that NPRL2 may be involved in epithelial-mesenchymal transition, gastric cancer stem cells, and responsiveness to chemotherapeutic agents in STAD (P<0.05). Furthermore, functional clustering analysis revealed that NPRL2 was involved in the mTOR signalling pathway, autophagy, and the amino acid starvation response (adjust P<0.05). In addition, NPRL2 was negatively associated with tumour-infiltrating immune cells while positively associated with immunotherapeutic biomarkers in STAD (P<0.05). Meanwhile, patients with high NPRL2 expression were predicted to have a better response to immunotherapy (P<0.05). Finally, a prognostic model constructed based on NPRL2-related genes could predict the prognosis of STAD patients (AUC =0.641), and the risk score was an independent prognostic factor for STAD patients (HR =4.855, 95% CI: 2.683-8.785, P<0.001). Conclusions: The present study provided a comprehensive analysis of the role and potential mechanisms of NPRL2 in STAD, suggesting that NPRL2 is a potential biomarker for the survival and prediction of immunotherapy response in STAD.

A Retrospective Study on Bile Culture and Antibiotic Susceptibility Patterns of Patients with Biliary Tract Infections.

Aim: This study aimed to provide profiles of microorganisms isolated from bile and antibiotic susceptibility patterns of biliary tract infections (BTIs) in our center. Methods: A total of 277 patients diagnosed with BTIs at the Second Affiliated Hospital of Harbin Medical University from 2011 to 2018 were included in this study. Medical records were reviewed to obtain clinical and demographic data. Bile specimens were prepared through endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiodrainage (PTCD), and percutaneous transhepatic gallbladder drainage (PTGD) under aseptic conditions. In those with positive bile culture results, blood cultures were concurrently conducted. The concordance of the results between bile culture and blood culture were also analysed. Results: Two hundred and sixty-seven bile cultures were positive, while 280 strains of micro-organisms were isolated. Among these, 76.8% were Gram-negative, 22.5% were Gram-positive and 0.7% were fungi. The most common microorganisms were Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis. Gram-negative bacteria we tested were highly sensitive to ertapenem, imipenem, tigecycline, and amikacin. Gram-positive bacteria we tested were highly sensitive to tigecycline, teicoplanin, linezolid, vancomycin, and chloramphenicol. For the 44 patients with positive bile cultures, a blood culture was also performed. Among them, 29 cases yielded positive blood culture results. Among those cases with positive blood culture, 48.3% showed complete agreement with bile culture, 3.4% showed partial agreement, and 48.3% showed disagreement. The most common microorganisms in blood culture were the same as in bile culture. Additionally, the proportion of Staphylococcus epidermidis was significantly higher in blood culture (P < 0.05). Conclusion: Our study provided a comprehensive analysis of the bacteria distribution and drug resistance profiles in patients with BTIs in northern China. Further studies should be conducted to validate our findings.

An unexpected strategy to alleviate hypoxia limitation of photodynamic therapy by biotinylation of photosensitizers.

The most common working mechanism of photodynamic therapy is based on high-toxicity singlet oxygen, which is called Type II photodynamic therapy. But it is highly dependent on oxygen consumption. Recently, Type I photodynamic therapy has been found to have better hypoxia tolerance to ease this restriction. However, few strategies are available on the design of Type I photosensitizers. We herein report an unexpected strategy to alleviate the limitation of traditional photodynamic therapy by biotinylation of three photosensitizers (two fluorescein-based photosensitizers and the commercially available Protoporphyrin). The three biotiylated photosensitizers named as compound 1, 2 and 3, exhibit impressive ability in generating both superoxide anion radicals and singlet oxygen. Moreover, compound 1 can be activated upon low-power white light irradiation with stronger ability of anion radicals generation than the other two. The excellent combinational Type I / Type II photodynamic therapy performance has been demonstrated with the photosensitizers 1. This work presents a universal protocol to provide tumor-targeting ability and enhance or trigger the generation of anion radicals by biotinylation of Type II photosensitizers against tumor hypoxia.

Au@mSiO2 core-shell nanoparticles loaded with fluorescent dyes: synthesis and application for imaging performance.

Here, Au@mSiO2 core-shell nanoparticles were easily synthesized by a one-pot method. Positively charged alkyl chains with different lengths were modified on the surface of the particles. Thus composite nanoparticles with different potentials and hydrophilic interface properties were prepared. Based on the charge properties of the shell surface, the process of loading dyes was simplified by the strong electrostatic adsorption between the particle surface and the heterogeneous negatively charged dyes. The fluorescence intensity and fluorescence lifetime of the loaded fluorescent dyes showed that the dyes could not produce effective tunneling in the mesoporous materials, which was limited to the surface of the particles, which is beneficial for the subsequent research on the loading or release of nanoparticles. After loading, the nanoparticles still exhibit a high fluorescence intensity, enabling dual-mode microscopic imaging (TEM and fluorescence).

Endoscopic Retrograde Appendicography: An Alternative Diagnostic Method for Acute Appendicitis.

PURPOSE: To evaluate the role of endoscopic retrograde appendicography for the diagnosis of acute appendicitis. PATIENTS AND METHODS: We retrospectively analyzed 33 patients (20 men and 13 women, average age 44±18 years) with suspected acute appendicitis between December 2016 and November 2018. Endoscopic direct-vision imaging or fluoroscopic endoscopic retrograde appendicography was performed to separate suspected acute appendicitis from actual acute appendicitis. The success rate, complications, and recurrence rate were recorded. RESULTS: Acute appendicitis was ruled out by normal endoscopic retrograde appendicography in 8 (24%) and confirmed in 23 patients (70%). In 2 patients (6%), appendiceal orifice cannulation failed. Colonoscopic findings in acute appendicitis were mucosal hyperemia and edema of appendiceal orifice (83%), outpouring of pus from the appendiceal orifice (74%), and swollen cecal mucosa (61%). Appendicograpic findings were either normal or in acute disease showed diffuse luminal dilation (diameter: 0.8±0.4 mm), partial stenosis (43%), stiffness or inflexibility (87%) and filling defects (22%). There were no complications during or after follow-up for a median of 13 months (IQR: 9-24 months). CONCLUSION: Endoscopic retrograde appendicography appears to be a reliable and safe method to confirm or exclude the diagnosis of acute appendicitis and prevent unnecessary appendectomy.

A Dual-Nanozyme-Catalyzed Cascade Reactor for Enhanced Photodynamic Oncotherapy against Tumor Hypoxia.

Tumor hypoxia is a typical characteristic of tumor microenvironment (TME), which seriously compromises the therapeutic effect of photodynamic therapy (PDT). The development of nanozymes with oxygen-generation ability is a promising strategy to overcome the oxygen-dependent of PDT but remained a great challenge. Herein, a dual-nanozymes based cascade reactor HAMF is proposed to alleviate tumor hypoxia for enhanced PDT. The hollow mesoporous silica nanoparticles (HMSNs) are constructed as an excellent nanocarrier to load ultra-small gold nanoparticles (Au NPs) and manganese dioxide (MnO2 ) shell via in situ reduction method, and further coordination with an efficient photosensitizer 4-DCF-MPYM (4-FM), a thermally activated delayed fluorescence (TADF) fluorescein derivative. With the response to TME, MnO2 can catalyze endogenous H2 O2 into O2 and subsequently accelerating glucose oxidation by Au NPs to produce additional H2 O2 , which is reversely used as the substrate for MnO2 -catalyzed reaction, thereby constantly producing singlet oxygen (1 O2 ) for enhanced PDT upon light irradiation. This work proposed a cascade reactor based on dual-nanozyme to relieve tumor hypoxia for effective tumor suppression, which may enrich the application of multi-nanozymes in biomedicine.